Bandit Alley
MODEL SPECIFIC => SUZUKI BANDIT 250 & 400 => Topic started by: gallant_pilot on August 30, 2014, 12:08:21 PM
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i recently built a b4 out of scratches, and did the engine,gearbox and etc..the problem started with idling,i replace the pilot jets (standard32.5)and rejeted the mains with 95.cleaned the carbs more than 10 times,synchronized them,replaced the o rings,checked out the needle and seats and it was just fine,floaters are great..my buddy is a bike technician and he helped me on that.bike used to flood first and then after adjusting the float height to very low,the flooding went away.but recently i faced new problems,still it smells too rich and any time if i start it the first try will work,otherwise if i dont keep the revs up by first crank,it wont start,specially in cold.even after riding for while and shuting down the engine,it wont start and it needs to settle down for while(10 to 30 min).then again it runs well and after getting warm,by stop signs,it tends to shut down with rough idle.so i have to keep the revs up or adjust the idle screw high.the bike struggles in low down and doesnt move properly,after a point it just guns up and rides nicely.then again when even the idle is fine when i pull the clutch the revs r not coming low easily and it slows down gradually.idle works fine just when bike is cold.but again sometimes if start it in cold,i feel like the engine is flooded as i have to open the throttle fully and it sounds like its working on 3 cylinders.recently the dude said that he doesnt understand the problem anymore.also the float level is too low( workshop manual says 14.6mm more or less and its now around 12.5 mm) .still i smell fuel on the bike and it also gets hot quickly.he also did some air screw adjustment on carbs while engine was running,but actually it made it worse even,specially on idling.please if u guys had the same problem and sorted it out,help me in this case.she is like my babe and i wanna enjoy riding it.this babe runs like a rocket and can beat any 600 while its on the high way.
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First off, I would suggest you work a bit on your writing skills because it's very hard to follow the story in my opinion. No punctuation and many different problems summed up after each other. :thumb:
Anyway...
I would suggest putting the carbs on their stock setup and going from there.
Why did you rejet the mains? did you re-jet the pilot jets also? If so why? (based on what?)
Unless you have a different airbox/filter the bike should run fine with stock carb settings.
This means 14.6mm bowl and 1.5 turns out on the pilot jets with needle in the middle. You can then work from there.
You says it sounds like its working on 3 cylinders.. you can easily check this by touching the exhaust header pipes.
You need to remove all other problems before fiddling with the carbs.
Other things to check:
Does choke mechanism work properly? Does it return?
How is the throttle valve on all carbs?
Do all the needles go up if you throttle without airbox?
Vacuum hose from left carb connected/not torn?
Small little o-rings under vacuum cap?
Not returning to idle quickly is usually a sign of bad carb sync or too lean mixture.
Don't forget you need to sync after change valve clearance.
Or you could do a dyno run for A/F readout and see what the problem is.
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What Squishy said!
Get everything back to stock settings and start over. Your float setting is way off and at least part of your problem. Even a heavily modified bike won't need more than 1 or 2 mm of float adjustment.
A
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first i have to apologize for my writing,i am not English and tried my best.
second thing is that the main jets were #102.5 standard and it was heavy on fuel.also i dont have problem with them,the last owner replaced the exhaust pipe and made it smaller without rejeting it. the pilot jets are also standard #32.5 according the workshop manual.i just put new ones. the throttle valves open properly without airbox.spark plugs are tested and they are brand new.bike has no electrical problem.but in idle by touching the exhaust pipes, i can see one of them is cold and its not one specific one,it shifts from 1 to 3 or 2 or 4.but at high revs they all get hot.i actually did the stock setting at the beginning and it was flooding.and the needles and seat are 100%,then we started the lower the float levels.choke mechanism works perfectly ,throttle valves open nicely and all needles go up with no hesitation,vacuum house also works 100% and the vacuum orings are in position,even i put some silicon around them to make sure that there is no leak.
to me it seems to be very lean at the moment,bcs last time the dude adjusted the air mixture screws,he made it lean i guess and the high revs problem started from that day.
now i am gonna set everything back to stock setting, and get back to you guys.
if u have any other suggestion,plz let me know before i strip the carbs,
by the way,i am from South Africa and the climate here is not same as the US,currently its spring time and weather is a bit chilli.
tx
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I'm not talking about your English. English isn't my native language either.
I'm talking about general punctuation/writing. You don't use spaces, paragraphs or capital letters.. you just write one wall of text. It's very hard to read.
Anyway with stock carb settings it should not flood.... why do you think it's flooding or running too rich? How do you know this?
You don't need to rejet after a new exhaust. At least not with the stock headers/pipes. My 400 runs fine with open exhaust.
Why not put it to stock settings and put it on the dyno for a A/F run? Saves you a lot of trouble.
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good advise for writing !
1- first of all, at the beginning after riding it ,the bike used to die on the way and by opening throttle fully it used to come back alive sometimes.
2-nowadays after running it ,the moment i switch it off,it doesnt want to start again unless i leave it for while.
3- rejeting the main should affect on high rev,not the idle and i dont have any problem with the fast running or fuel.she doesnt struggle on high way at all.not loosing power even.
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hey guys !
i set the carbs back to the stock setting and started it.(didnt struggle that much)
float level(14 mm) air mixture screw 1.75 turn.
without the airbox on,the idle is fluctuating and number 3 ( second from the left) doesnt get hot,its just a bit warm. also when i put my hand to check the suction on all,this one doesnt react and doesnt have any vacuum.
i stopped working on it till i read yot comments.
please i am waiting for u guys to gimme ideas before i put everything back.
tx
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I would start off by checking valve clearances and then a compression check.
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u think it can be kind of tight on that one?
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Unless the valve clearance and/or compression are WAY off, the cylinder should run and the pipes should get hot.
Normally, checking for compression is always a good thing to do because even when everything is perfectly working but you have bad compression, your engine will not run well.
However in this scenario I would remove the sparkplug from cylinder number 3 as you call it, and clean it. (since you say the carbs are clean)
My 400 works fine for 30000KM but in my experience it's very sensitive to a good spark.. especially when your spark plug drain hole is clogged up with dirt or when you haven't run it for a while.
Use a steel brush to clean the spark plug and check if the wiring is good.
If the carbs are clean and in stock settings.. it can't really be a fuel problem unless the carb doesn't get fuel at all. You can check this by opening the drain plug.
It can't really be an air problem either because the other 3 cylinders are firing and you say the carbs are clean.
What remains is a good spark, valve clearance and compression.
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Hi,
how many O-rings did you found and replaced in each carb? There are totally of five O-rings (each of different size) in each carb. One under top cap, one under pilot jet screw, two seals float assembly into carb body and one is burried deep inside carb and seals needle emulsion tube. You need to remove whole slide assembly to get to this one. If it is cracked (which usually is), carbs may leak even with float level set up properly.
Another little detail: GSF400 mikuni carbs should have rubber plugs covering hole of pilot jet fuel intake. This is due to relatively small vacuum on idle RPM. if these are missing, you'll get rough idle and there's nothing you can do about it except fitting the plugs back. It is possible that some of previous owners removed them because he thought he is smarter than manufacturer.
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i replaced the orings and all 5 orings are fine.
i put one oring around the rubber plugs as well and it is seald properly.
problem is number 3 which doesnt have vaccum suction on idle. but at high revs it works nicely.
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Squishy !
is it possible for the spark plug to just make sparks on high revs? bcs at high revs the number three comes back to the system and it works..
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yes, it is possible. it may be internally damaged. try to change spark plugs between cylinders.
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Squishy !
is it possible for the spark plug to just make sparks on high revs? bcs at high revs the number three comes back to the system and it works..
Yes it's possible.
When my spark plug drain hole was quite dirty and it had rained all day, 1 cylinder would stop working when it was idling.
When I got in high RPM it would start to work again.
This problem causes a lot of starting problems because you will try to start it on 3 cylinders basically.. if you haven't run it for a while it will hardly start..and may even cause the other cylinders to get flooded causing more problems.
I've also had it the other way around where it would work at idle but not when giving full throttle. Also caused by rain and dirt.
If you are 100% sure the carb's idle circuit is clean and all the mechanisms on the carb work (perhaps carb is so out of sync that on 3rd cylinder the throttle valve is closed while the others are open?), then it almost has to be spark(plug) related.
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Another thing I would check is for wear on your emulsion tubes, if they are particularly worn you'll be getting too much fuel at the lower end which can upset the idle and low end running.
I've just bought new to replace mine and even a visual inspection shows how worn the old ones are
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not neccessarilly spark plug, but ignition. Incluging caps and wires.
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not neccessarilly spark plug, but ignition. Incluging caps and wires.
Yes that's why I said spark(plug) ;).
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i sync the carbs abd they look good.this is exactly the one which is the refrence for sync the others.
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i sync the carbs abd they look good.this is exactly the one which is the refrence for sync the others.
There is not one carb to use as reference for the others..
You sync 3&4, then 1&2 and then 1+2 & 3+4
Make sure you use the throttle stop screw to set higher (I think its 1700rpm?) but in your case set it so they are all running.
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guys today i noticed something new and it might be the problem!
1-the carbs i believe,they are good now as everything is set back to the stock setting.
2- i didnt have chance to do the compression test yet,but today i found some water mixed with kinda foamy oil leaking out of the engine which i guess coming from the gasket.
i upload the photo and will be waiting for tour comments.
if is the gasket, what is your suggestion? replacing the gasket or anything else?
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Might be coolant with oil... check the levels. Yes could be the result of a leaking gasket.
Unless the leak is very bad, it should still run. If you hold your hand in front of the exhaust while it's running.. do you feel vapor/oil/coolant?
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i checked it out, and there is no oil or coolant coming out of exhaust,which i guess the leakage is not that bad yet.but still on idle the same pipe doesnt get hot.
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did you performed compression test? (if you already written about it, i am sorry, i didn't go through this topic very thoroughly) maybe you should to test with engine cold and then with engine warm. normally cold engine should give lower compression readings than warm but if you are leaking compression into oil / water lines you may see that this particular cylinder won't have compression increased accordingly to others.
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as i said before !
today while i was riding it,the bike started jerking and i open the throttle,suddenly it just started to mess around and work on 3,no power at all. i rode it back home and i think the gasket is gone now.
but there is no smoke or steam coming out of the exhaust pipe.also i can see that leakage is still there.
now if you guys have suggestion about replacing the head gasket, plz tell me in details.
1- do i need to take the head for engineering or i can lightly skim it on marble and fine(1500) sand paper?
2- i cant find a brand new gasket here and the agent says i have to wait for 3 weeks to bring from Japan
3- do u suggest the copper gasket instead of SUZUKI steel gasket? my friends said the copper can work much better than steel so i have to get it cut first if i use the copper.and it would be accessible for me.
4-in general.do you guys think the problem was the gasket from the beginning which made me think there is carb problem?
however after building the engine,i didn't put new gasket and used the old one,just sprayed it with normal paint aerosol to seal it.
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re - torque all head bolt and valve cover bolts.
If that doesn't work try new gaskets. While you are there, look for any cracks in the water passages.
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guys any idea about using aluminum head gasket or copper?
i wanna get it cut asap and wanna know if the aluminum gasket is working!
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
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Wow leave for a year or 2 and the squids on here are still having carb issues!!!
Carbs will always present issues, won't they? I think that part of the difficulty we're seeing today with Bandit 400 carbs is the result of Emulsion Tube wear.
The problem is that emulsion tube wear is hard to see and identify: http://www.factorypro.com/products/Mikuni_needle_jet_buy.html (http://www.factorypro.com/products/Mikuni_needle_jet_buy.html)
Now 102.5 are too lean from stock period! So going even leaner is just stupid.
This is probably a true statement, but only if the set of carbs don't have worn (oblong) emulsion tube holes. Unfortunately the B400s are getting pretty long in the tooth and worn emulsion tubes are more and more common.
Once the emulsion tubes begin to wear into an "out of round" state the carbs become richer and richer. I don't know if you can actually tune around the situation but people sure to try which might explain what the Original Poster in this thread is trying to do.
Apparently Mikuni saw the emulsion tubes as a "consumable item", something that was just going to have to be replaced on a regular basis, but most owners of motorcycles with Mikuni carbs didn't get the message.
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I've got almost 40000km on my bike and thè emulsion tubes are as round as the day they left the factory! 2 things contribute to worn out emulsion tubes, the major factor is jet kit needles and to a lesser degree high levels of ethenal in the fuel.
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Having just replaced a set of emulsion tubes on a stock bike with standard needles and approaching 46,000 miles ~ 74,000 Kms I can only imagine its a combination of fuel and emulsion tube material.
New tubes have completely solved the massive richness issues I was having. As for tuning around the problem, you can to a point by leaning off the needle but eventually the tubes will need replacing.
On 750 and 1100 oil cooled motors Emulsion tubes are, as Greg says, consumables, made infinitely worse by harder needles be they Dynojet or otherwise.
I replaced 6 or 7 sets in a 2 year period at the Dyno place I worked at, mainly on Suzukis
Cheers
Chris
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
What makes you think that?
My 400 has 100 stock jets and runs great. (BST33SS)
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I've got almost 40000km on my bike and thè emulsion tubes are as round as the day they left the factory! 2 things contribute to worn out emulsion tubes, the major factor is jet kit needles and to a lesser degree high levels of ethenal in the fuel.
I agree there's probably a very wide range of possible lifespans for Mikuni emulsion tubes, probably influenced most heavily by various things people do to their carbs (performance mods and clumsy maintenance) that have the unintended effect of increasing the rate at which the emulsion tubes get worn.
I would bet that the emulsion tubes last the longest in carbs that are never modified.
When I bought my B400 last year and disassembled the carbs I found that they'd obviously been messed with quite a bit over the years. First, the springs in each carb had been cut shorter than their original length by about 4 coils of the spring winding. One of these shortened springs was installed upside down (with the cut end downward on the needle while all the others had the un-cut tight-coiled end on the needle). Also one of the needles had a washer used in place of the original spacer. I don't know if the needles were OEM or some sort of aftermarket brand, but they seemed unstable and waggled in their seats in the slides. This would certainly allow them to rub against the emulsion tubes.
Obviously one of the prior owners of my Bandit was trying to get better performance out of it and we all know that the default assumption of the hobby level tuner is that "richer is always better". This sort of thing is probably what causes Bandit 400s to eventually become completely un-tuneable and eventually end up stored away in a shed or pushed into a dark corner at the back of a garage. Because modifications to richen up the engine when the emulsion tubes are fresh will end up making the bike unrideable and untunable when the emulsion tubes start to wear (which causes it to richen up even further).
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
What makes you think that?
My 400 has 100 stock jets and runs great. (BST33SS)
Hundreds of hour dyno tuning yes they "run" with 100 but they run better , run cooler, and make more power with 110. Oh and the Gsxr 400 where this engine comes from has guess what 110 mains stock Mmmmmmm. The only reason they came with 100's was to pass emission tests
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Having just replaced a set of emulsion tubes on a stock bike with standard needles and approaching 46,000 miles ~ 74,000 Kms I can only imagine its a combination of fuel and emulsion tube material.
New tubes have completely solved the massive richness issues I was having. As for tuning around the problem, you can to a point by leaning off the needle but eventually the tubes will need replacing.
On 750 and 1100 oil cooled motors Emulsion tubes are, as Greg says, consumables, made infinitely worse by harder needles be they Dynojet or otherwise.
I replaced 6 or 7 sets in a 2 year period at the Dyno place I worked at, mainly on Suzukis
Cheers
Chris
Where did you find a set of emulsion tubes for a bandit. Suzuki has been out of stock for years over here in Canada
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
What makes you think that?
My 400 has 100 stock jets and runs great. (BST33SS)
Hundreds of hour dyno tuning yes they "run" with 100 but they run better , run cooler, and make more power with 110. Oh and the Gsxr 400 where this engine comes from has guess what 110 mains stock Mmmmmmm. The only reason they came with 100's was to pass emission tests
Not saying I don't believe you :). Just curious. My 400 does about 185km/h and pulls great. Only thing I've noticed is that after 12000rpm it drops in torque a bit.
Do you also have experience with the BST33 carbs? It might be different jetting wise compared to usa/can BST32.
edit:
This page says gsx-r 400 has 100 mains http://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Spec_sheet.pdf
Thanks
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Having just replaced a set of emulsion tubes on a stock bike with standard needles and approaching 46,000 miles ~ 74,000 Kms I can only imagine its a combination of fuel and emulsion tube material.
New tubes have completely solved the massive richness issues I was having. As for tuning around the problem, you can to a point by leaning off the needle but eventually the tubes will need replacing.
On 750 and 1100 oil cooled motors Emulsion tubes are, as Greg says, consumables, made infinitely worse by harder needles be they Dynojet or otherwise.
I replaced 6 or 7 sets in a 2 year period at the Dyno place I worked at, mainly on Suzukis
Cheers
Chris
Where did you find a set of emulsion tubes for a bandit. Suzuki has been out of stock for years over here in Canada
Ordered them through Robinsons Suzuki in the UK, Mine is a Canadian import from what I can tell, so I ordered on the US part no. although I think from what they said I had the last 4 in Europe, the UK spec ones were on 5-6 week back order from Suzuki Japan.
They are still available but seemingly becoming unobtainium
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Partzilla says they have needle jets available. Could be an experiment for someone.
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wow,i see this post is going into new things.
i never knew the emulsion tubes can cause problems,however after checking them recently.i still see them in very good condition,all the holes are perfect and its rounded shape completely ;
anyways!
i had to strip the top end myself ,and i found 6 valves are leaking.specially on # 3 which wasnt getting hot,2 intake and on ex were leaking badly.
i lapped them all and the seal properly now,also i got an aluminum gasket cut and also did some skimming on the head at home.
my bike performs nicely with 95 main jets and fuel economy is better with them, i also cleaned that little hole from the main passage to the pilot jets which i never knew they do exist .
i am gonna reassemble the head before weekend and test it.
one thing i noticed that there was petrol in my oil after flashing it.i can easily smell the petrol in it.
so guys, u still think its the emulsion tubes which need to be replaced?
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petrol in the oil is often a sign of a stuck float needle. The needle will stick open and gas will just fill up the cylinder, leak around the ring and fill up the crankcase.
A
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
What makes you think that?
My 400 has 100 stock jets and runs great. (BST33SS)
Hundreds of hour dyno tuning yes they "run" with 100 but they run better , run cooler, and make more power with 110. Oh and the Gsxr 400 where this engine comes from has guess what 110 mains stock Mmmmmmm. The only reason they came with 100's was to pass emission tests
Not saying I don't believe you :). Just curious. My 400 does about 185km/h and pulls great. Only thing I've noticed is that after 12000rpm it drops in torque a bit.
Do you also have experience with the BST33 carbs? It might be different jetting wise compared to usa/can BST32.
edit:
This page says gsx-r 400 has 100 mains http://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Spec_sheet.pdf
Thanks
The 5 gray market bikes I worked on all had 110 mains stock! If your only getting 185kph then your missing a lot of top end power, mine did 225 before I started to play with the engine. This was with the 110 mains. And yes I've a lot of experience with the 33mm carbs as canada has alway gotten unrestricted bikes!
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Wow leave for a year or 2 and the squids on here are still having carb issues!!! There are hundreds of back posts on how to get a 400 jetted correctly. Now 102.5 are too lean from stock period! So going even leaner is just stupid. A stock 400 is very happy with 110 mains, stock pilot, stock float height. Raise the needle one up from stock. Oh and use stock mikuni jets not some crappy jet kit.
What makes you think that?
My 400 has 100 stock jets and runs great. (BST33SS)
Hundreds of hour dyno tuning yes they "run" with 100 but they run better , run cooler, and make more power with 110. Oh and the Gsxr 400 where this engine comes from has guess what 110 mains stock Mmmmmmm. The only reason they came with 100's was to pass emission tests
Not saying I don't believe you :). Just curious. My 400 does about 185km/h and pulls great. Only thing I've noticed is that after 12000rpm it drops in torque a bit.
Do you also have experience with the BST33 carbs? It might be different jetting wise compared to usa/can BST32.
edit:
This page says gsx-r 400 has 100 mains http://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Spec_sheet.pdf
Thanks
The 5 gray market bikes I worked on all had 110 mains stock! If your only getting 185kph then your missing a lot of top end power, mine did 225 before I started to play with the engine. This was with the 110 mains. And yes I've a lot of experience with the 33mm carbs as canada has alway gotten unrestricted bikes!
225km/h? That's the gsxr400?
No way the gsf400 can do 225... many sv650 can't even go 225.
Maybe i'll get myself some 110 mains and see what happens....110 with stock airbox...yes?
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Umm yes a bandit can do 225 and the Sv's round here are good for 240ish. By the at I've owned my bandit since new! By the way your riding the wrong bike if you want good gas mileage.
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Umm yes a bandit can do 225 and the Sv's round here are good for 240ish. By the at I've owned my bandit since new! By the way your riding the wrong bike if you want good gas mileage.
Final post before we hijacked his topic too much :stickpoke: :bandit:
At the moment I'm doing 20KM on 1 liter..
Just to be sure #110 mikuni size right? (because I know Dynojet/factory pro sizes are different). And stock airbox/filter?
Thanks.
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Buddy your beating a dead horse if your trying for good mileage. If you want mileage get a passport 70. The best you will get on a "properly" running 400 is mid 30 mpg. Period! This engine puts out more specific HP than the Gsxr1100 of the same vintage. Don't be so "F"ing lazy and search out the hundreds of posts on here about jetting and mileage!
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Buddy your beating a dead horse if your trying for good mileage. If you want mileage get a passport 70. The best you will get on a "properly" running 400 is mid 30 mpg. Period! This engine puts out more specific HP than the Gsxr1100 of the same vintage. Don't be so "F"ing lazy and search out the hundreds of posts on here about jetting and mileage!
Where did I mention anything about wanting to get good mileage? You're the one who brought it up out of no-where.
Btw I did read the jetting info topic but literally nobody is running 110 mains. Only found 1 post about 110 from the old topic and it appears to be from you (Theif400).
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Cause your tracing your mileage by jetting!!!! Read the whole jetting thread. Everything you squids want to know has been documented on here years ago! Stop being so lazy!! Nothing happening now isn't new and has been we reported on here
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Cause your tracing your mileage by jetting!!!! Read the whole jetting thread. Everything you squids want to know has been documented on here years ago! Stop being so lazy!! Nothing happening now isn't new and has been we reported on here
Dude, you need reading glasses..
I never even mentioned the word mileage until you brought it up.
I'm not tracing my mileage. I don't even care about mileage... :banghead:
edit: I think you're confused with poster gallant_pilot (OP). He mentioned fuel economy...
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Everything you squids want to know has been documented on here years ago! Stop being so lazy!! Nothing happening now isn't new and has been we reported on here.
Wrong. The B400 is aging, it's getting older. That's what I was pointing out earlier in this thread.
All of your old jetting information just assumes the carbs have healthy emulsion tubes in them, but as the B400 ages this is less and less likely to be true.
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The bandit 400 was old when the jetting thread was started. You can't tune around worn emulation tunes. The only solution is to replace them. And forget about trying 110s if you're running a jet kit. The needle taper on the jet kit allows more then enough fuel with the supplied jets.
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The bandit 400 was old when the jetting thread was started. You can't tune around worn emulation tunes. The only solution is to replace them. And forget about trying 110s if you're running a jet kit. The needle taper on the jet kit allows more then enough fuel with the supplied jets.
I'm running stock carbs with stock airbox and slip-on exhaust.
I got the needles with adjustable clips. (set to +1 richer)
Gonna try 110 .. only cost €7,50 so
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So I tried 110 but will post results in jetting thread (http://forums.banditalley.net/index.php?topic=9085.msg108538#msg108538)
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hello again guys!
after a long time, i finally stripped the engine,got the head and barrels skimmed and lapped the valves.
there is no leakage from the valves and everything looks fine.
1- i did the timing exactly same as what manual says.( 20 pin from 3 on EX to 2 on IN)
2- spark plugs are good and i have purple,blue spark.
3- set the carbs to stock setting.
4-new battery is on the bike.
now the bike doesnt wanna start at all.the starter turns the engine but there is no single sign of starting.
i have no idea anymore.
do u guys have any suggestion for me?
its GK75 engine
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Could be anything.
1) Check compression first
2) Recheck timing
3) Check spark on all 4 plugs
4) Make sure the carb gets fuel, and don't forget the vacuum hose. Check choke mechanism.
5) Make sure airbox is clean.
If you have compression, correct timing, 4 healthy sparks, fuel and air, it must start.
So one of the 5 is wrong.
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i checked everything !
spark is there,fuel is enough in the carbs,timing is exactly as the manual shows,i tried it with and without air box.compression is good as i did recon on head and valves,rings and pistons are in very good condition.
if any of these is not write,i must at least get a very tiny small combustion.but there is nothing at all.
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i checked everything !
spark is there,fuel is enough in the carbs,timing is exactly as the manual shows,i tried it with and without air box.compression is good as i did recon on head and valves,rings and pistons are in very good condition.
if any of these is not write,i must at least get a very tiny small combustion.but there is nothing at all.
Well, I would recheck the above 5 points.
1) What were the compression numbers?
2) Double check timing
3) If it sparks it doesn't mean it can spark under compression. Make sure the sparks are in good condition.
4) Check everything on carbs: vacuum rubbers, choke mechanism, throttle valves, vacuum hose, intake rubbers.
You could also check the valve clearances, even when compression is good they might open too far or something?
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try to check spark with two nails with ends 8mm apart instead of spark plug (manual show how exactly). you should still get spark. if not, shorten the gap and test how small will fire the spark. especially in case you have original, untouched, stock ignitor which tends to fail often. In colder weather even replacing previously working spark plugs for equally heat-rated new ones can do miracles and replacing HT wires can do even bigger ones. (if it was not already performed).
and one note: check if you have HT wires connected correctly. i know it is dumb but i happened once to me when I was fiddling with one of my B400s that I swapped wires between coils. I suddenly got no spark for no apparent reason. Also, If carbs sat dry for some longer period bio-ethanol probably present in gasoline might clog passages inside carbs.
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today i replaced all plugs with new ones and i have spark on all 4.
tested the compression and it is alryt.
checked the timing and its also perfect.
cleaned the carbs again.
still nothing :banghead:
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Sorry to hear you're still having problems. Here's something to consider and check.
I just scanned back over all of the posts in this thread and I didn't see any mention of the bike's Ignition Control Box.
The Bandit's Ignition Control Box can easily be the source of your problem. The most delicate part of the Bandit's ignition control system is the two very small wires that connect it to the Signal Generator (which is a variable reluctance pulser located under the engine's left-side cover).
The Signal Generator was obviously produced separately by a sub-contractor (probably Nippon Denso Corp.) and this parts provider constructed it with only enough wiring to get a couple of inches (centimeters) past the rubber oil-seal stopper. When the Suzuki assembly technicians built it into the Bandit's wiring harness they used crimp-on connectors. These crimp-on connectors are rigid while the rest of the Signal Generator wiring is flexible. This creates a point at which the wire naturally flexes when any bending force is applied.
The Signal Generator wiring can fray and split at these crimp-on connections. You should carefully inspect the Signal Generator wiring to determine the condition of its wiring to the Ignition Control Box. Inspect the wiring from where it comes out of the upper-rear corner of the engine's left side cover to where it reaches the two-wire connector plug in the main wiring harness that leads to the Ignition Control Box.
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Also, the Bandit's Ignition Control Box is very sensitive to the amperage spikes. It's okay to "jump start" your Bandit from a car battery as long as the car's engine isn't running. If you do this with the car's engine running the amperage is too high for the Bandit's Ignition Control Box.
During your maintenance difficulties and trouble-shooting if you have attempted to "jump start" your Bandit from a car with the car's engine running the capacitors on the circuit board inside your Bandit's Ignition Control Box will be blown out and it will not function.
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Greg you have a point.i have tried to jump start it many times with car battery while the engine was running.
now the only thing might be gone is the CDI,which i will get it tested tomorrow.
tx for advises !
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If you have access to somebody who really knows electronics and is good at soldering then your CDI (Ignition Control Box) could be repaired. The high-amperage induced by the car's alternator will blow capacitors, which is bad of course, but once the capacitors are gone there won't be any further damage to the rest of the CDI (the capacitors are the weakest part and they give up their lives to protect the rest of the CDI). This leaves you with a situation that can be fixed.
A skilled electrician can identify the blown capacitors and replace them. This requires a good quality Multi-Meter to identify the bad capacitors (or you can simply replace all of the capacitors), a de-soldering kit to remove the bad capacitors and a precision soldering station to put the replacements in.
Opening up the CDI to get at the circuit board without doing too much damage to the plastic case is a bit of a challenge but it can be done (it's similar to getting into the insides of anything produced by the Apple computer company).
Here is a link to a very old thread here on the BanditAlley.net forum which was a discussion between members about how to do the capacitor replacement: http://forums.banditalley.net/index.php?topic=431.0 (http://forums.banditalley.net/index.php?topic=431.0)
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Yes it's possible for it to be the CDI but I would always check this last because it's hard to diagnose and can be expensive to replace.
Even still when it has a spark and everything else is good the bike should at least give a sign of life.
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testing it will cost me 5 $ max. also i do have spark.
i am really confused,if everything is fine,why it doesnt fire up.even a single fire would not be unexpected.
i attache a sample picture of timing which i got online and it looks exactly same with my timing.
i removed the spark plugs and put my finger inside the hole and started the engine,i can easily feel the compression which is pretty good and enough for a single fire up.
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That's not how you decided the compression is good right? :bandit: Numbers please
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you are right about the compression.its not the right why,but its enough i guess for a single fire.also after replacing the gasket(before skimming the head) i put everything back and it just started easily.but the water was pissing out and i had to get the head and barrels skimmed and lapped the valves.i tested the valves with vacuum tester at engineering and it was fine,also at home i did the liquid test by putting paraffin and was also good and no leakage was seen.then after reassembling it back.i got this problem.
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grg737: wait what? high amperage induced by car alternator? amperage pushed through electrical circuit is direct result of voltage in circuitry and electrical resistance of circuit itself. While resistance is given by circuit construction it's (more or less) constant. Voltage is regulated by regulator to be somewhere between 13,5 - 14,25V. Not different from voltage output of bike alternator. Then current in circuit is given by Ohm's law.
Thus unless car used to crank the bike has faulty regulator or ancient mechanical regulator there's little chance to damage ignitor by using running car to crank the bike. The only difference between car alternator and bike alternator is that voltage output from car alternator drops less with higher current draw than bikes alternator.
If something died from using running car to crank the bike it would die sometimes in nearly future anyways!
But ignitor may be faulty. Capacitors tend to dry out which decreases their capacity and filtering abilities. I have replaced them on one of my ignitors. This may / may not help.
Another problematic part of original ignitors are final stage high-gain bi-polar transistors which do all the rough work and pass quite a huge currents through ignition coils. These tend to raise their resistance over time which causes to generate more heat and in turn raise the resistance even more until engine stops to work. This causes smaller voltage/current to be applied to ignition coils and thus weaker spark.
Even if spark is present when plug is out of engine it may not be able to crank. Even with brand new plugs. I experienced this once when the only action which helped was to replace the final stage transistors with new ones.
Bad news is that current electronics is using unipolar transistors for high-current switching circuitry so there are no transistors available offering switching capabilities of original parts nowadays. IIRC original transistor had h21e (gain coefficient) of over 500. Current transistors which are available have h21e coefficient at best of 1/3rd of original. In my ignitor darlington-type TIP150 from fairchild worked well and provided enough gain to create spark which is able to run the engine (not only spark out of engine). It is also mechanically and electrically compatible so you do not need to adjust PCB/circuitry or change position of anything inside. Just desolder old and solder new.
If final stage transistors need to be replaced can be examined by connecting terminals to oscilloscope and read voltage between ignitor terminal connected to coil and ground during the phase when transistors are open. Ideally it would be 0 but as the transistors are old they build some resistance which in series with quite a low resistance of ignition coils causes voltage buildup on transistor. I cannot provide figures of what voltage is already bad and which is good but if voltage is different for left / right coil and / or if it is larger than 1V I would replace final stage transistors for new ones.
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See how that happened, works every time...
It's a little-known fact that there are highly-qualified electrical engineers walking among us all the time. They normally refuse to offer electrical help or advice until, that is, somebody who doesn't know much about the science of electronics says something that doesn't quite make sense. And that person is ME.
You're welcome.
So, apparently the "don't jump-start a motorcycle from a running car" is an absolute myth.
This is actually very interesting to me because it begs the question: Why is this caution/warning about doing damage to the motorcycle's electrical system so widespread?
I'd hazard a guess that this erroneous caution/warning to the unwashed masses (of electricity-ignorant riders) grew up out of the more basic danger of damage that will result from something like accidentally hooking up the jumper cables to the wrong polarity on the battery.
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Yes it's possible for it to be the CDI but I would always check this last because it's hard to diagnose and can be expensive to replace.
Even still when it has a spark and everything else is good the bike should at least give a sign of life.
i finally got the CDI tested today and they said its faulty.however i didnt believe them as they are bunch of screwed ppl,so i took it to aeronautical electronic guys and asked them to have a look on it.
i did the compression test myself today,however it was headache to find adapter for it.anyways,i did some dry and wet test.my GOD it was nothing not even 100 Kpa.then i added some oil and cranked it for few second and it went up to 700 on one and the others 450 and 500 more or less.
with regards to what i have done on the head and valves plus the new aluminum gasket i put,it should be the rings or pistons,however i checked the barrels and they were fine and smooth and free of any single scratch, also my mechanic said that the pistons and rings look fine.
now whats next?
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Told ya, do a proper compression check.
Yes it does sound like piston rings but for them to be 100kpa they almost have to be missing or you have a hole cylinder walls.
You did have the throttle wide open during the test, right?
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it might sound funny,but honestly it was my first time to check the compression.the dry test,i just cranked the engine for like 3 seconds and didnt hold the throttle open.but after adding oil i did open it and cranked it for longer.the readings are as below:
from the left
1- +- 650
2- +- 250
3- +- 400
4- +- 350
now how can i do the dry test again while the oil is still there and what do the numbers have to say?
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The oil will drain down and get into the oil pan. That's ok.
Hold the throttle open and crank the engine.
It should be >800kpa on all 4 and between them not more than 200kpa diffierence.
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well,i am gonna leave the bike for while and the oil probably will drain out into the sump.i will try it again and see what it reads.
is there any way that we can catch up on whatsapp.viber or maybe imessage?
if yes,plz add me and text me there as it would be quicker sometimes than the forum!.
+27837667118
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greg373: for same reason why constant voltage-type chargers have usually capacity rating in form from-to and/or switch for bike/car (by which I don't mean switch 6V/12V which is separate): car alternator can deliver quite a good portion of amperes until output voltage starts to drop. let's say 40 amperes when idling. If you are cranking your bike using external power source there's strong assumption that your battery is discharged. Fully discharged battery has quite a low resistance so you can easily apply so much current to charge the battery that it will boil, electrodes will bend or any sort of different bad thing (TM) can happen.
edit: while people are dumb enough to dry their pets in microwave oven they may be dumb enough to crank/charge their fully discharged batteries (in fact it is not needed to be much dumb to do that) by running car and boil them.
Bike generator has less power so even if by some miracle you manage to crank it up with completely dead battery, voltage drop would be so huge that ignition stops working. And even if not it won't have enough power to fry your battery.
BUT with fried battery there's no voltage stabilizer in circuit and running bike without bat you can damage both generator and ignitor.
If you are cranking the bike with running car connected and with bat at least slightly charged it will have higher resistance and chances to charge it too fast are smaller. But by no means this could directly damage ignitor itself.
Bandit's ignitor is simply not much reliable. Youngest one is more than 15 years old. Most of ignitors "on the road" are 20+ years old. Electrolytic capacitors contain fluid which creates their capacity. They are long and heavy compared to their electrode dimension so they are sensitive to vibrations even despite the fact they are glued inside ignitor by flexible glue. They are also sensitive to heat. Heat and vibrations are two factors which are present in huge amount on bike. So capacitors tend to die during the years. But more heat-sensitive parts are final stage transistors. On both mine Bandits ingitors were dead. One was repaired by myself (first: final stage transistors were replaced as described above which brang the ignitor back to life then: replaced capacitors to avoid need to disassemble it once again). Another bike has it's ignitor replaced for several years. First bike was cranked for several tens of minutes after ignitor was re-mounted after repair using running car with no damage at all. Battery has lower capacity but it is already quite old and was sitting discharged for maybe one year so it was considered as already dead.
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after almost 24 hrs, i did another set of compression test!
i think the time was enough for all the oil inside the barrels to settle down.
dry test wet test
4- 250 200
3- 450 450
2- 200 250
1- 550 550
my guess is that the rings are still good.
but now what else can cause this low compression?
1-head gasket is aluminum freshly cut
2- head bolts are tighten 25 n/m
3-valves have been lapped and valve seats are cut
4- timing is as manual
5-barrels are free of any scratches.
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So that's with throttle fully open?
Well I've no idea what you've done with the valves but something is definitely wrong there. (lapped the valves???)
Either it's screwed up or the valve clearances are completely off.
As I said before, check those as well.
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stripped the head today again.
tested the valves with water and soap and by blowing hard inside the intake and exhaust ,not a single tiny leakage even.
what is the possibility of the bad timing by one tooth? can it cause that huge difference?
this link is an old post for timing on forum
http://forums.banditalley.net/index.php?topic=9298.0
i also attache another photo .
so which one is correct?
i remember the first time my mechanic did the timing just like the one in the link and this time i did it like the photo( which is exactly like what manual shows)
i checked the valve clearance and adjusted them as manual with the filler gauges.
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hello guys!
i took the barrels off today to check the pistons.and guess what !
almost all my compression rings were pinched inside the grooves,so wet test and dry test wouldnt make a big difference.
what can cause that problem?
is it possible to take them out and reuse them again?
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hey guys,any comment about the timing?( with regards to my post recently)
i am assembling the head and want to know which one should i choose !
tx