I can't take it any more

[Dennislav]

I've been able to ignore a few things about my bike (96 B6) for a while now, but I'm starting to get sick of them.

First:  The bike doesn't run "right" especially when cold.  If I don't let it warm up for a good long time (five to ten minutes) and even sometimes when I do, it will bog and die if I try and engage the clutch under 3,000 rpm, no matter what throttle position its in.  After about 10-20 minutes of riding it usually quits doing that but it'll start again if i let it sit for even five minutes.  I'm not sure if this is "normal" but it sure doesn't sound like it to me.  Also, the idle (cold or warm) is always wandering a bit.  

Since I got the bike just over a year ago, I have cleand the carburetors, adjusted the valves (they were almost all tight), replaced the number 2 and 3 cylinder coil and boots, and synchronized the carburetors twice.  I ran into a problem with sync'ing the carbs both times.  The number two cylinder would momentarily and randomly read zero or negative suction.  I caulked this up to the cylinder not firing so I changed the coil and boots (the resistance over the leads was much higher than it should have been also) but I think I saw it do it once or twice when i sync'ed the carbs the last time.  Also, I couldn't make the bike idle at 1750 rpm (suggested speed in the manual).  I tried adjusting the idle using the knob on the bottom of the carbs but as soon as i got it near 1500 rpm it would shoot up to 3000, and vise versa.  So i tied to do it with the throttle and the same thing happened.  So i sync'ed them at as close as i could get to 1500.  

I have a feeling that should be good enough but I'd really like to know why my motor wont run freely between 1500 and 3000 rpm, why my idle sucks, and why it keeps bogging.

Next:  Recently there is a clunk coming from my transmission (at least i think so, its kind of hard to tell when I'm riding).  It seems to only happen under 4000 rpm.  At first i thought it was pre-igniton, but its not quick enough to be.  I read on another thread that someone's front sprocket was loose, i have yet to check that.  I'm hoping a piece of a gear isn't floating around down there or something crazy like that.  Next time i change the oil I'm going to cut open the filter and search for shavings.

Anyway, if anyone has any ideas please let me know, I'm getting really tired dealing with my bike dieing as I'm pulling through intersections.

[rider123]

Sounds like you're crazily lean or have some vacuum leaks. Does the bike run better with the choke on? I'd take a look at the plugs and see what's going on. If they're bone white you are super lean. Could also be fuel starvation from either a faulty petcock or a plugged up tank breather hole. Have you tried running the bike with the cap off? Also try running the bike on prime to see if the petcock diaphram is a little sticky. Check the plugs right away. If you are lean don't drive like that you will fry your pistons. try to sort out why you are lean first. Do you have a jet kit in there? Or are the mixture screws drilled out? You could then richen up the mixture. Has the bike always been this wonky? It could be that your pilots jets are clogged as it seems to run on the mains (>3000) semi-ok. Need more info. Do a plug check and tell us what colour they are.


If you want you could try an "Italian" tune up. Take the seat and document tray out of the bike so you can see the intake snorkle. Rev the bike up to say 5-7000 rpm then let go of the throttle and cover the snorkle. This creates a shitload of vacuum and will suck out any crud in the carbs. It might be an idea to drain the floats before doing this then fill with fresh gas.

[B6mick]

I need more information to be able to help you bloke.
How many miles has the bike done, what sort of miles has it done, ie has it been flogged or has it been mothered. What plugs are in it, what type of fuel do you use. It seem your doing all the right things, but I sure there is something probably, stupidly simple that will have it running like a spirited B6 should.

[tacoman]

I'm assuming your bike has stock jetting?  These B6's are so lean from the factory that 10-15 min warm ups are the norm.  Shut the thing off for a few minutes and you have to do it again.  i would recommend this.  Get the Holeshot stage 1 kit.  When the carbs are apart clean them and give em a good once over.  Any deformed diaphragms etc.  Follow the settings Dale recommends and go from there.  It should run fine.

[Dennislav]

I’ve had the bike for just over a year now and its always been this way.  It was a bit worse before the valve adjustment and the carb sync, the two things that I was hoping would fix this.  Its got almost 20,000 miles on it and it has fairly new NGK plugs in it.  I fill up with 91 or 93 octane.  Im not sure how the guy before me rode but I don’t ride it too hard, most of the time.  The bike is stock and mixture screws are solid.  I gave the carbs a damn good cleaning when i got it so I'm fairly certain that they are spotless.  

I pulled the plugs tonight and they do look white.  They defiantly aren’t bone white, but enough to be noticeable.  If I did have a vacuum leak where would it be from?  I checked the caps on the 1-3 carbs and the hose from the #4 carb to the petcock.  they are all solid.  The boots between the carbs and the engine are on correctly, not cracked, and the clamps are all tight.  What else is left?  I think I’m going to take apart the petcock and replacing the filter (there’s a filter in there right?) and any other components in there.  

I also tried running the bike on 'prime'  No help there.  What should happen if i try and run the bike with the fuel cap open, and where is the tank breather hole? I have noticed a pretty strong gas smell from the gas cap lately.  I cleaned the sealing surface tonight too, ill see if i can still smell gas tomorrow.

Other than that, I’ve been thinking about getting a jet kit.  I heard recently that they improve gas mileage along with power.  Is it OK to run a stage one jet kit with a stock exhaust?  Other than possibly not tuning the carbs correctly, are there any drawbacks to the jet kit?


Thanks for all your suggestions and input.  If you have any more ideas, please let me know.

[B6mick]

I’ve had the bike for just over a year now and its always been this way.  It was a bit worse before the valve adjustment and the carb sync, the two things that I was hoping would fix this.  Its got almost 20,000 miles on it and it has fairly new NGK plugs in it.  I fill up with 91 or 93 octane.  Im not sure how the guy before me rode but I don’t ride it too hard, most of the time.  The bike is stock and mixture screws are solid.  I gave the carbs a damn good cleaning when i got it so I'm fairly certain that they are spotless.  

I pulled the plugs tonight and they do look white.  They defiantly aren’t bone white, but enough to be noticeable.  If I did have a vacuum leak where would it be from?  I checked the caps on the 1-3 carbs and the hose from the #4 carb to the petcock.  they are all solid.  The boots between the carbs and the engine are on correctly, not cracked, and the clamps are all tight.  What else is left?  I think I’m going to take apart the petcock and replacing the filter (there’s a filter in there right?) and any other components in there.  

I also tried running the bike on 'prime'  No help there.  What should happen if i try and run the bike with the fuel cap open, and where is the tank breather hole? I have noticed a pretty strong gas smell from the gas cap lately.  I cleaned the sealing surface tonight too, ill see if i can still smell gas tomorrow.

Other than that, I’ve been thinking about getting a jet kit.  I heard recently that they improve gas mileage along with power.  Is it OK to run a stage one jet kit with a stock exhaust?  Other than possibly not tuning the carbs correctly, are there any drawbacks to the jet kit?


Thanks for all your suggestions and input.  If you have any more ideas, please let me know.

Cool I got some info to work with
Engine is still near new, then.
Ok which NGK plug are you running?
Next thing is when you cleaned out the carbs, did you clean the emulsion tubes, and all the little holes?
The plugs do say lean, but a blocked or part blocked emulsion tubes will give you a lean out. Sorry only one way to clean them, take them out.
Hmmm you yanks and your plugged mixture screws, take them down to the local shop and get them unplugged.
My advise don't bother with the stage one kit it you have it working right, other wise you couild be chasing your tail for ever.
The next thing is the exhaust, hmmmmmm, When I got my 96 B6 the owner before me mothered the poor thing. It ran like crap, the Little B6 engine is a spirited thing that needs a good old flogging, mine been flogged for years and just keeps on getting better. Now thew stock jetting and the stock exhaust coupled with being mothered can clog the thing with carbon, but in your case it really does sound like carbs, and with those sealed mixture screws, and I would almost lay a dollar on it that your elmusion tubes are way blocked.
But all I can say for now is change your plugs one grade cooler, that may help with the lean out, and get your carbs off, and down to the shop and get adjustable mixture screws in, or should I say the sealing plugs out.
Also run a higher octane fuel, the denser nature of the higher octane may help richen up your mixtures, but I really dont think so, but it may be worth a try.

[Red01]

B6mick:

Dennislav: I fill up with 91 or 93 octane.

Also run a higher octane fuel, the denser nature of the higher octane may help richen up your mixtures, but I really dont think so, but it may be worth a try.

Mick, he's already running the highest octane available.
Remember, the US uses RON+MON/2 for octane ratings, so the numbers are lower than countries that use only RON for the same fuel.
(RON = Research Octane Number, MON = Motor Octane Number)

I'd recommend running regular (87 in the USA) instead of premium. That's what Suzuki recommends. Keep in mind higher octane fuel is harder to ignite than lower octane, so you'd get a more complete burn out of regular than premium - and this might help address the white plugs better than trying to go to an octane even higher than what's available at the pump.

[tacoman]

I would try shimming the needles.  Its easy because you don't have to pull the carbs, just unscrew the top caps.  You can get the spacers at Radio Shack from what I understand or you can order them from Sudco (www.sudco.com).  I would try 2 shims on each carb and see how it is.  Mine was tad rich with 2 so I went to 1.

[B6mick]

Red01:

B6mick:

Dennislav: I fill up with 91 or 93 octane.

Also run a higher octane fuel, the denser nature of the higher octane may help richen up your mixtures, but I really dont think so, but it may be worth a try.

Mick, he's already running the highest octane available.
Remember, the US uses RON+MON/2 for octane ratings, so the numbers are lower than countries that use only RON for the same fuel.
(RON = Research Octane Number, MON = Motor Octane Number)

I'd recommend running regular (87 in the USA) instead of premium. That's what Suzuki recommends. Keep in mind higher octane fuel is harder to ignite than lower octane, so you'd get a more complete burn out of regular than premium - and this might help address the white plugs better than trying to go to an octane even higher than what's available at the pump.

My mistake 87 to 91 rated octane is 3 year old camel piss to us down here. 98-96 is the good stuff here.

[Dennislav]

Ive got NGK 'R'  CR9EK's on the bike now (its the general recommendation from the manual).  When I cleaned out the carbs I made sure that I got every hole possible and I did it pretty thoroughly (i think i used a can and a half of carb cleaner).  I used to have an old Suzuki moped so i knew that all the little passages had to be spotless.  

Which tubes are the emulsion tubes?  

I think its going to rain tomorrow and Sunday so I might rip into my carbs this weekend.  I'll probably drill out the caps and play with the mixture screws.  Ive never actually tuned a carburetor before (other than playing with the screws on a lawn mower or leaf blower and then it was just enough to get it to sound right).  What am i looking/listening for when i try and adjust the screws?  How many turns out do you guys have yours set to?

I also read in the manual that i should be running 91 octane (RON).  Is that equivalent to the US 87?

Thanks again guys.  If i get to the carbs this weekend I'll keep you all posted.

[Red01]

The emulsion tubes are what holds the main jets in. On the "microfiche" they're called jet holders.

Yes, 91 RON is 87 RON+MON/2

[Dennislav]

Alright,

I pulled the carbs and drilled out the caps.  I was debating cleaning them again, i got impatient and I didn't.  I set the pilot screws to 1 7/8 turns out like it says in the manual for UK bikes (I’m assuming that the setting should be the same).  I tried to adjust the carbs using the method in the Haynes manual (set idle, adjust one carb at a time till idle rises as much as possible, reset idle, lather rinse repeat).  My idle didn’t move so I’m kind-of at a loss.  Am I doing something incorrectly or is there a better way to do it?  

Anyway, a jet kit is sounding better (at least I'm defiantly keeping it in mind).  I know Holeshot and Dynajet are both pretty competitive, any advice on which is better?

[Daytona]

I think I can say I'm glad i don't have carbs any longer! I know one thing use it or loose it. Leave em site! Hold your breath it runs ok! Your problem could be a host of things. Since you say (and others) that the 600 is cold natured, i would say go with the after market kit and check every thing. This could be anything from float level, plugged passages, etc etc. One thing 1.75 turns out on the primary's seems too little. I know on my 1200 setting the primary's was a waist unless it was idling 1500 to 1700. unless the carbs are sync'ed spot on. It idled on just 2 carbs before a carb sync so how could the primary's adj!    

[tacoman]

Get the holeshot kit, it works great on the B6.  Also, Dale is just a phone call away if you have problems.  I think it would be best to take the carbs apart, clean, then install the jet kit.  This way, you've eliminated a lot of variables like dirt in carb, wrong jets, and bad mixture settings.

[Daytona]

="tacoman"]Get the holeshot kit, it works great on the B6.  Also, Dale is just a phone call away if you have problems.  I think it would be best to take the carbs apart, clean, then install the jet kit.  This way, you've eliminated a lot of variables like dirt in carb, wrong jets, and bad mixture settings.

Here here!!