Mikuni question

[steve lebow]

I have a set of Mikuni RS34 mm carbs on my 83 GS1100E
The problem is after accelerating the bike keeps pulling after i shut down the throttle. Yes I have the push pull throttle set up, and I am forcing it closed by rolling the throttle shut during deceleration.
Im not sure what causes this. maybe pilot jets or pilot air jets, i mean the throttle is closed but the bike keeps pulling.

thanks

[almarconi]

Are your cables adjusted properly?

[rudy]

What happens if you're just idling in the driveway and blip the throttle? Same thing? Does it eventually come down?

[almarconi]

Hey Steve,
Where in Maryland are you located??

[psyguy]

keep a look at the carbs buterfly shaft while twisting the throttle back and forth and see if indeed the buterflies follow your action on the throttle

[steve lebow]

Hey Steve,
Where in Maryland are you located??

I live in Annapolis

[steve lebow]

keep a look at the carbs buterfly shaft while twisting the throttle back and forth and see if indeed the buterflies follow your action on the throttle

No Butterflies, Just flat slides. they do follow the throttle action because i manually close the throttle by hand. its a push pull throttle.

[steve lebow]

What happens if you're just idling in the driveway and blip the throttle? Same thing? Does it eventually come down?

Yes it does the same thing while idling in the drive way. If you blip the throttle it will stay up for a few seconds then settle back down to its idle.
Let me tell you, its very unnerving coming off an exit ramp.

[don_gibb6512]

Mine do the same thing but not that bad. I have yet to figure it out exactly. I have some time this weekend to work on it and I'll let you know if I figure anything out. It might be a binding cable but a lean condition can make for a slow to very slow drop back down to idle. One thing you might do is get the bike warmed up then take the air box or pods off. Look at the slides and see if they're coming down with the return of the throttle. If not, you know it's a cable issue. If they are, then it's a lean mixture problem. At least, that's my plan of action. HTH.

Don


p.s. If you get it figured out, please post. Thanks.

[almarconi]

Hey Steve,
If you can't get it sorted out, the guy that helps me work on my bike might be able to help you out. He has his own shop, prices are reasonable and he is very knowledgeable. His name is Steve, the company is Shaffers Motorsports, located in Brooklyn, Maryland. His number is 410-636-6999.

He did the state inspection on my KZ, mounted 2 tires, replaced chain/sprockets and synced the carbs for $200. Eventhough I supplied him the parts, I thought this was very reasonable for the labor. I've know him for several years and he has always treated me well.

[gmkiller50]

do it happen when its cold? I have an 83 gs1100 with the same carb and only when its cold will it do that but when it warms up no problems....did you check your throttle cables? i had a problem with my cables too.

[rapidray]

Either the pilot jets or the mixture screws are LEAN! Try adjusting the screws first. Check the float heights also. Ray.

[don_gibb6512]

According to Mikuni and Sudco, the Pilot fuel screws are supposed to be turned out only 1/8-1/2 max. Turning them out adds more fuel, so out is richer. I had mine turned out 1 full turn with 17.5 pilots. The plugs were burning ok, maybe just a tad rich but I was still having some lean surging at 1/8 - 1/4 throttle and the idle speed would hang up some when coming down from a higher rpm, after the bike was warmed up. I just switched to 20 pilot jets with 1/4 turn out on the Pilot fuel screw and man, I think I've got it. Finally.

What REALLY made the difference here, and I was chasing my tail for a VERY long time on this one, was adding the coil relay mod and getting a solid 12v to the coils. This is critical otherwise you could tune the carbs until Hades freezes over and it just won't ever be right.

So, my current set up is: 1980 GS1100ET with Mikuni RS34 Flat Slides. 117.5 Main jets (may bump that up to 120 eventually), 17.5 Pilot Jets, Pilot fuel screw turned out 1/4, needle set at 3rd groove from top. Stock settings otherwise.

Focus on the Pilot circuit if your trouble is 0 - 1/4 throttle, which is where it probably is most of the time.

Good luck. If I think of anything else, I'll be sure to post it.

Don

[steve lebow]

Fixed it

I would have sworn that my cables were ok, in fact they looked ok but the pull cable was too tight not allowing the pull cable to go all the way back down. there should be some play in the cables. also the 2 and 3 intake boot clamps were not tight enough allowing air in to the system when closing the throttle. this was found by spraying carb cleaner with the extension attachment on the nozzle at different areas of the intake boots. when i hit the right spot the bike would stumble or stall while idling. i replaced all the clamps with thin good quality worm drive clamps. also i had the idle mixture screws turned out almost 2 turns. man was this off. the bike purrs now and shuts down the way it should now.

thanks for all your advise