Poor Mans Stage 1 kit

[Octane]

I thought I'd share this...
Rider123 donated to me 4 112.5 main jets for my B12.  It took a while but I finally got around to doing the valves and pulling the carbs off to fit these up. In doing so I discovered I had adjustable needles. So after fitting the jets, setting the needles to full rich, setting the pilot screws to 4 turns out and cutting a 1.5" hole in the top of the airbox lid I was off to go testing. the bike also has a slip on exhaust. The low and mid range was smoother and the zone above 6,000rpm felt according to my arse dyno stronger. After a week of riding I pulled the plugs to inspect. The centre and ground electrodes were clean with a hint of purple hue. The base ring was sooty though. Today I decided to pop in my K&N. Went for a ride and the bike feels fine. Same as before but maybe a hint stronger.
I don't know why with Dale's stage 1 kit he says not to use a K&N but on the stage 2 he does. I'd really like to know the reason. Stage 1 on a B1250 he includes a K&N. I'm also confused as to why you would leave the snorkle in the airbox after opening up a 1.5" hole in the top Woudn't you pull the snorkle out to give you more area? On a stage 2 B12 kit you slice the whole top off the lid to leave it W I D E open and with a K&N fitted.
Anyhoo, in another week I'll pull the plugs again to see how they are fairing. Happy with the result so far for my tight arse tune. Only thing is I need a racetrack to test it fully as I like my license intact. There are quicker bikes out there I know but I'm now rediscovering that I bought a Bandit for riding and touring  - not racing. There's nothing wrong with tuning your bike for optimum performance for a given purpose - is there? Ride safe.

[rider123]

If you pulled the airbox lid off you'd need way more than just 112.5's. If you want put the stock filter back in and take out the snorkle which will give you some more air in there to test if you need to maybe enlarge the top 1.5" hole. If you use a K&N it will be lean in the midrange and up top as I've tried it myself. Try putting it back with the stock air filter and pulling out the snorkle which will enlarge the snorle area to 2" diameter instead of 1.5" but I believe if you take the snorkle out you lose a bit of low range torque. However if the bike gains more power and drives smoother, what you could do is pop the snorkle back in there and enlarge the top hole from 1.5" to 2" or whatever you need.

eg:

snorkle in 1.5" hole
1.5 " hole

3" total.
--------------------------------
no snorkle - 2" hole
1.5 " hole

3.5" total.<---more air. Maybe too much? You could tape over the snorkle hole slightly if necessary to test.
-------------------------------


Alternate:

Enlarge the top box hole(Maybe use a file). It's 38 mm(1.5") so maybe 2mm a time, ie 40 mm then test 42mm then test, etc.

Also before cutting holes, etc. Maybe turn in the mixture screws a 1/4 turn and see if that cleans up the plugs. It could be at 4 turns out your maybe a little too much. Is the top metal where the spark jumps to the electrode have sooty bits on it?


Bad ascii diagram again :-(
    
          
      _________  
     I          __
    I      __/__\__   <--------------Metal Tip, sooty deposits with sooty base ring could be rich on pilots try a 1/4 turn in for fun to see.
   I      /            \<-----------Electrode
   I___/_________\__< ----base ring
   I                       I    
   I                       I  

[Octane]

Hey Rider123!
It's the base ring which is sooty and you can sort of wipe it off. The electrodes themselves are clean but have a hard coloring to them (purple - whatever that means).
For a full house carb rejet with the K&N pod filters and special needles - what size jets are people running? When does the main jet take over from the pilots? Or better still is there a laymans text on how these carburettors work?
I know - sorry for all the questions.

[rider123]

Try turning the mixture screws a 1/4 turn in and ride around a bit, see if that cleans up the base ring a bit. The purple bits are usually just the crap they put in gasoline these days sometimes when I switch stations the plugs change colour a bit. Usually the base ring being sooty means that you need some more air in there so for fun try putting the stock filter in and pulling the snorkle or see if just a 1/4 turn in on the mixture screws help

From what I gather here on the board for stage 2 you need like 147.5's or 150's and Dales special needles. I hear that tuning a stage 2 is tricky, you may want to buy the kit from Dale as he will help you tune it.

http://www.holeshot.com/bandit/bndt_b1201_stage2.shtml

I think if you make the 1.5" hole on the top a little bigger it will probably clean up the jetting or alternatively just lean it out a bit. Taking out the snorkle to test takes all of 20 seconds to unscrew the two philips screws on the document tray and is easily reversable. If you take out he snorkle and find it too lean then you can just tape up tiny bits of the 2" snorkle hole until it's perfect, then at least you know sort of how much to enlarge the hole.

For example if the 2" hole was taped up a quarter that is 1.5" which you won't go past because that will be the same as having the snorkle in. So say you test the bike with the snorkle out and find it a tad lean, say you tape up an 1/8th of the 2" hole and now its perfect. So now you know that when you put the snorkle back in there you have to enlarge the top cut hole to 1.75" with the snorkle in. That way you get the best of both worlds, you have the snorkle velocity stack for lower end/low mid range torque but also have a big enough hole(1.75" in this example) for the upper mid and top end power.

Going to a stage 2 you will lose some low end as you basically just have the carbs open and the air isn't accelerated and smoothed out with a velocity stack(the snorkle). In an ideal world the intake would be variable like the fantail exhaust on a fighter jet. At lower rpm it would be smaller to give maximum torque but at higher RPM the intake would expand to allow more air for maximum horsepower.

Stage 1 is a comprimise between maximum power and low end torque, you get good numbers for both however you don't get theoretical maximum torque and you don't get theoretical maximum power. However for drive-ability the stage 1 is excellent and for %99.99 of people out there because chances are they aren't towing a trailer or wide open on a drag strip and it's still way better than stock at any rpm or throttle position.

[DaveG]

keep in mind that 2x1" holes does not equal a 1x2" hole
pi r squared

many variables are involved here. Filter, inlet opening, outlet restriction or lack there of
My 02 B12 still seems a little lean with 112.5's and a 3/4" hole in the air box. Bigger hole was more lean, actually too lean.
The 3/4 hole was a compromise, just right in hot weather but in the cold (like today) shows signs of very slightly lean.  Any setting is really just a compromise.

My main reason for jetting was to get rid of the coldbloodedness and obvious lean condition after adding a bolton.
I have also shimmed needles and adjusted pilot screws.

You really just need to make small changes one at a time (ONE AT A TIME) until you find the combination that works for you.

[Octane]

Well I left the K&N in but opened up the pilot screws another 1/4 of a turn - now at 4.25 turns out. Had to adjust the idle speed up.
Just completed 200km of every type of riding you can do - city stop start, periods of sustained 100km/h, mountain ascents and decents (x2 sets of) and in cool and warm weather (it was sunny and then it rained on top of the mountains).
Bike ran flawlessly - seriously it ran like a true champion. I pulled the plugs and took a picture (will post it up) the sooty base ring is gone - plugs are clean but slightly brownish in colour. I think I might have it sorted - maybe.

[rider123]

Awsome! Only 100?

[Octane]

Yep, I left the hero riding to the others on the mountin that day. Drag test & tune days come up fairly often here. Cheap enough too. $45. Track days on the other hand are expensive IMO. One day I'll do one but not in 2011. The only other thing to add would be an ignition advance.

[rider123]

I imagine your probably getting a little more power than the standard stage 1. An ignition advancer will crispin up throttle response but you may have to go to mid-grade gasoline if you are getting pre-ignition. I have the holeshot advancer and it's super easy to install and comes with a new gasket to boot.

Now that I've been thinking about it I may put my spare 112.5's(I've got the ones from the holeshot kit in storage) in there in the spring, and give it another shot. I have the 110's in there and 1.5" is too much air I've had to tape up some of the hole to fix the mid range and upper range leaness. My problem is that I have the larger pilots which makes the bottom end rich and with the hole too large the upper lean. So I think if I open up the hole back to 1.5" and pop the 112.5's back in and put the original 15 pilots in there or turn the mixture screws in, I should be perfect. With the larger 112.5's and the 17.5's at the recomended 3.75 turns out it was just too rich. As you can see by my sig I'm at 3 turns out and I still have some sootyness down low. Since I'm one pilot size up my equivilant turns out with 15's are 4.5 turns out(one size up or down = 1 1/2 turns). I may turn the screws in another 1/4 turn and adjust the hole to match which would probably make me good at least until spring when I can experiment again. I'm glad it turned out so well for you.

Here is the advancer link. I'm sure it's not too much to ship to Ozzyland. I did notice a difference with the throttle response with the advancer, it's a wallop of power with no lag.

http://www.holeshot.com/bandit/bndt_advancer.shtml

[Octane]

Well, I finally got off my arse and posted the plugs image. Numbered 1 to 4 left to right.
I'm still happy with the performance but I reckon the advancer would add a bit of an edge to it. Don't forget I'm running a K&N filter too.  These plugs have done about 10,000km. From memory they are about $10AU each here for JR9B's. I bit rude IMO. Might have to get some shortly.

[rider123]

They look pretty good there, maybe a bit rich down low but other than that it's fine. The third from the left you can see that the tip of the electrode and the base ring have some sooty deposits but it looks good to me. Maybe if you wanted to turn in the mixture screws 1/4 turn and see how it drives. You may need the bottom end a bit rich to compensate for the K&N filter. The first one on the left looks the richest. Try a 1/4 turn in for all and see what happens, if the bike drives weirder then just leave it as it is. I'm assuming from left to right is the cylinder arangment right? Ie plug 1 is cylinder 1 etc. If so then don't worry about number 1 because if the bikes on the kick stand it will get slightly more fuel until you upright the bike.
Best one out of the bunch is number 2. Though when you take pictures of the plugs with the flash makes the dark parts darker and the light parts lighter. Maybe try a sunny day outside it gives a better realistic contrast.


If you really want you could pop in a fresh set of plugs totally clean and brand new and use these as spares. It might give you a more accurate reading. And yes the advancer will make the throttle response more snappy and will make a slightly more complete burn of the gas so the plugs may lighten up a bit.

Maybe go for a long ride a little faster than 100 on the highway for an hour then take a look. It will clean up any previous deposits.

[STI-REX]

G'Day Maaate

Greetings from a fellow Aussie

I have actually bought the Dale walker kit and also have adjustable suzuki oem  needles , with the kit set up as dale describes  1.5 inch hole in the airbox lid with 5 washers under the needle (I left the needle on the middle clip just to see what it was like ) and the 110 mains 3.75 turns on the mixture screw mine was rich at idle but slightly lean on the needle and was not quite pulling all the way to the top of the rev range it felt like it was leaning out ( 5° advancer fitted ) factory air filter

with the 5 washers under the needle (middle clip ) it is the same as the clip being at the bottom of the needle plus 1.5 shims approximately

Now i have the 112.5 mains installed with 3 shims under the needle on the bottom clip with the mixture screws on 3.5 turns out from seated and the 1.5 inch hole in the air box lid + the 5° advancer fitted with a new clean factory air filter

The thing pulls like a steam train all over the rev range now and is so smoooth all the way to the red line  with plugs nice and clean around the ceramic insulator and just the slightest tinge of black around the threaded part after 3000km's on this set of plugs with mixed riding

[rider123]

Well I'll have to fish out those 112.5's out of storage then. I was in the same boat way too rich down low, horridly lean up top. I have turned the mixture screws in to 2.75 with 17.5's which equals about 4.25 turns on the 15's half the airbox hole taped up and it drives perfectly but I'm not getting the full effect of the extra airflow. I can tell at high RPM(>7500) its wanting more airflow, its not rich it's just hitting a max airflow wall. I will pop in the 112.5's in the spring and try again with the 1.5" hole totally untaped. Hell there is one guy here with 112.5's with the hole taped up 1/2. I definitely need more jet.

Even with the screws at 2.75(4.25 equivalent) with a half a 1.5" hole, I can tell it's still a touch rich down low(plugs confirm it) but I put in the next size up pilots as per the recommendations and it probably wasn't necessary. Since I'm 1 size up on the pilots that equals about 1 1/2 turns on the mixture screws. Probably the screws should be around 2.5(4 turns) or so but I definitely need those bigger mains. Also if I put the bigger mains in there and the airbox is opened up it will probably need around 2.75 anyway or maybe even 3 turns out, so I might as well leave it until the spring. It's also cold out so a little extra juice can't hurt it.

When I set the screws to 3.75(5.25 equivalent!) with the 112.5's as recommended it was just too rich, ran super awesome up until it started getting hot. However with the screws set to more where the they should be it probably will be fine.

I should also add I have a Muzzy slip on and mid-pipe which looks pretty wide open which may explain why I need more jet. It's almost just a piped hole going from the exhaust collector box to the exhaust cap. However, ironically it's alot quieter than my friends Yosh even though its a smaller pipe, it was also repacked last year so it's not like its just nothing in there.

To give you an example my plugs look like your number 2 plug but my electrodes are much whiter but the base ring is about the same(slightly rich down low) but really if you look at the outside of the ring you can see it's a little lighter, in a perfect world it would be closer to that colour. However it's better to be slightly richer than leaner. If you can get all the plugs close to what number 2 looks like it should be good. For fun I would turn the screws in a 1/4 turn for fun and see how it goes, on a warmer day here I may do the same however I'm still a little lean in the mid and upper range so I have to compensate a bit with the pilots.

[STI-REX]

I forgot to add that I am running a yoshi tri oval slip on with a yoshi link pipe

And just yesterday the post man dropped off a set of Delkevic headers to have a play with and i may need to change the jetting again as the inner diameter of the delkevic is almost the same as the outer diameter of the Stock down pipes ( no twin wall setup like stock ) and so much lighter
Just weighing up whether or not to get the new headers ceramic coated

I am locate within 50 kilometers of the Queensland  coast and at an elevation of less than 250m above sea level currently it is reaching 34-38° c with 45 -50% humidity during the day and it is not even summer yet

In the winter it rarely gets below 20°c during the day and is usually the best time to ride

[deanozx10r]

I havent tore into my bike yet and just wondering what brand of jets I can use mikuni or keihin or are they the same??? I am going to put together this with the 112.5s combo, my bike has the holeshot can so it should be close to what everyone here is doing. And I seen some where about setting the float level anyone know the right height??

Not sure if this is jetting problem or just gumbed up junk. The bike run fine when im not riding it like my racer, but when I start using more of the top end and midrange after a bit it really hesitates and has no power. My guess is probibly one never been cleaned and stock jetting after the original owner put the can on. Like I said I havent tore in this so not sure if the jets are stock or not.