VM carb throttle adjuster problem.

[Suzuki mad]

I'm really new to VM carbs on GS1000S's as I have only ever had CV carbs.

In the centre directly underneath the middle of the carbs is a round knob which I take is the throttle stop adjuster. So what does it do??

I've turned this knob hoping to bring the tickover down from 1500rpm to about 1100 but to no availe. It doesn't change the slack on the throttle cables. It doesn't lift the revs so what is it doing?

All I wanted was to bring the tickover down to 1100rpm.

I'I re-read the manual but I am guessing that something is not connected correctly here.

Any suggestions before the carbs come out onto the bench.

Suzuki mad

[Ghostgs1]

The knob is for idle speed adjustment. The throttle cables may be in need of adjustment also, if the knob does nothing. Ray

[srsupertrap]

Something is misadjusted . . . the VM GS1000 carbs use a push pull throttle cable set up. The slack in the throttle cables can be adjusted in two places. Below the throttle grip housing were the cables exit you will find a couple of jam nuts that adjust the cable slack. The second place is were the two cables attach to the carbs.

Since you stated the round knob has no effect on the engine idle this would infer the the throttle cables are misadjusted (too tight) and one of them ( likely the pull side ) is holding the slides open.

Take off the Gas tank and loosen up the jam nuts underneath the throttle grip so they have no effect on the slide position. Then adjust the cables were they attach to the carbs. The pull cable should have a slight amount of slack.

[hampshirehog]

Good advice above - if your revs aren't dropping it's cable adjustment. I'd also check that the adjuster was actually sitting in the threads - there's a lot (an excess?) of adjustment on it and I would have thought if you'd wound it fully in your bike would be revving its head off. (It's a normal RH thread by the way).

[Suzuki mad]

Thanks guy's.

So thats why when you rev it it drops back to about 1700 then slowly goes to 1500 but its an instant rev up when you touch the throttle. For what your saying my guess would be that the pull side is tight.

I can't adjust the throttle ends as the lock nuts are seized solid. Rust.

Suzuki mad

Is

[Big T]

Pull the tank and adjust the cables where they run into carbs.

Use some Seafoam spray (do you have that across the pond) on the throttle side. Give it a spritz daily - it will actually reduce the rust

[Nessism]

High idle could also be a vacuum leak.