1982 GS1100GK - Intermittent issue - Engine died today - Help needed

[MtnManCA]

And I did check the gas cap vent: it was clean, no obstruction.

[MtnManCA]

Did another ~80 mile test run today. Bike ran very well, no hesitation.

[MtnManCA]

The hesitation came back. Sticking carb slide(s)?

Hello,

The occasional hesitation came back. On almost every ride the bike starts, idles and runs great 99% of the time but - especially at barely opened throttle - the hesitation/shuddering occasionally happens.

As before, whacking the throttle wide open helps. The typical scenario is that the bike runs great for 10-40 miles or so, then has short episodes of hesitation and then runs fine for the rest of the ride.

Because whacking the throttle helps, I am suspecting that the issue is vacuum-related. It does not seem to be related to the vacuum pet cock. I went on a longer ride with the pet cock in the PRI position and the usual hesitation occurred regardless.

Do you think a sticking throttle slide could be the culprit? I checked the diaphragms and they feel pliable and have no visible tears or holes. The slides easily slide into the barrels. Should I polish the barrels and slides?

[MtnManCA]

Assuming that only one of the four carb slides sticks, would this actually lead to a noticeable hesitation or shuddering?