above 3000 rpm

[Anonymous]

Hello All,
Well I sorted out some of my bike's problems. I adjusted the clutch which soved the problem of a rise in rpm with no increase of speed. I guess I just learned out what clutch slippage is! :roll:

But a couple of problems remain: 1. Plugs are still fouling on all four
2. Above 3000 rpm the engine races
and won't come back down.
I have checked for intake leaks (none) which could explain the racing, but with fouled pl;ugs I find this hard to beleive, since an intake leak would cause a lean condition. Could a higher flow petcock cause the fouling?
Would I need to rejet the carbs for a higher flow petcock? I think not. But I would like your expertse! 79 gs 850 emigo pods stock 4into2 without baffels rejetted carbs. Also Bike won't stay at idle without throttle.
MANY THANKS WISE ONES

[Billy Ricks]

Fuel flow from the petcock wouldn't cause this. It's either jetting is too rich, timing is retarded, or both. The choke circuit could also be leaking allowing raw fuel into the intakes. Your carbs are non CV type so you are lucky. Trying lowering the needles a notch at a time and see if it helps.

[lhanscom]

Petcock should not cause these problems, the only way it could is if your float needles weren't doing their job. If that's the case it could cause the problem you're having. It sounds like you're rich on the idle circuit. Try tightening your mixture screws a bit. It's also possible that you're lean on the needle, but rich on the idle. One thing at a time though.

[Anonymous]

what and where is the idle curcuit system. I assumme that it controls idle within the carbs. I took of the pods and the carbs are misting out a gas vapour.

thanks

[Detman101]

The idle circuit is composed of the mixture screws and the pilot jets I believe.

Dm of mD

[Anonymous]

I have vm 26mm carbs. Does anyone know where the air screw is located. I know it is either the one on the bottom of the carbs it has a yellow paint stripe on it, or it is the screw on the top right hand sie of the carbs next to where the pod filter sits. Do I gently bottom out the screw and do 1 1/2 to 2 turns out?

[Billy Ricks]

Here's a page on VM tuning.

http://www.lafishmag.com/CarbTuning.html

[Billy Ricks]

There is suppose to be a downloadable VM tuning guide here.

http://www.mikunioz.com/vm_tuning_manual.htm