GS550 Carb Sync and Idle Speed

[Anonymous]

Gang

I'm having problems with sync'ing the carbs on my 1978 GS550...

I start off with the idle set at 1750... According to the manometer, carb #3 is not in balance with 1, 2 and 4. If I adjust it to be in balance, the idle speed goes up to >2500 and I can't get it to come back down by adjusting the idle speed screw.

Am I correct in that the adjuster screws simply lift the the jet needle? Or does the adjuster raise and lower the throttle valvle..

Thanks in advance... I'm perplexed

Tim
2002 Concours
2000 KLX300R
1979 Iron Butt'd GS550 with Pod Filters, 4-1Pipe, Dyna 3, and very confused carburetors

[Anonymous]

The adjuster screws raise and lower the slides and the needles.

[Anonymous]

right.. and the needles are further adjusted by the clips...

So.. is the course of action to lower the valves as far as possible, then set the idle speed with the idle speed screw, which would then give me "room" to balance ? Balancing seems to raise the idle speed, and with the valves the way they are now I can't lower the idle speed once they're balanced..

Thanks
Tim

[Anonymous]

Number 3 is your reference point. You balance the others to it.

[AOD]

#3 shouldn't be adjustable. balance the other ones to it.

where you located btw? my 550 needs a balancing...

~Adam

[Anonymous]

ok.. figured it out..

#3 is non-adjustable in the later year CV carbs.. Mine's fully adjustable.

In a past life in software support we had an expression for folks who asked questions for which there was an obvious answer ---> RTFM.. Read the Fr**kin Manual..

I knew this too.. you have to plug the vacumm line that goes from the petcock to the #3 carb with a golf tee. !! Doh !

Anyway... did that. Its balanced fine now. For anyone else in the San Francisco area we'll now be running seminars on how to read the manual.!

;-)
Thanks all
Tim