tickover speed lowering, vacuum fuel tap?

[DaveWatts]

Hi,

What I am finding when I momentarily gas my bike (1980 GS1000G) then let it settle back to an idle, the revs go very low and then slowly pick up again to the correct idle speed. I think the fuel levels in the bowls is temporarily low. I think this is probably related to the vacuum fuel tap. When I gas the engine the fuel in the bowls is consumed, then when I shut of the throttle there is little suction and the diaphragm maybe closes and then only slowly opens when the bike slowly creeps up to idle speed again. The carbs have recently been serviced and the valve needles checked etc.

What do you think, is it a vacuum fuel tap issue?

Cheers

Dave

[rphillips]

Naw, that just doesn't sound right. Run it in the PRI position, if that corrects the problem that's it. If not, keep looking.

[DaveWatts]

The the PRI position didn't change things, but then I went out for a run, filled up with fresh petrol, then when I got back blipped the throttle and the tickover was solid. Either the bike is very cold blooded or pretty sensitive to petrol quality.

Cheers

Dave

[rphillips]

Don't forget to take it back off PRI. & Congrats