I haven’t had a chance to run the Bonneville since January 2006, owing to work and travel commitments.
It now starts, and runs, but won’t idle. Not even when well warmed up.
I did notice that it took a long while for the carbs to flood when the ticklers were first depressed. So had the fuel dried up in the carb? But I always leave the fuel taps on to prevent that happening.
I went through the whole carb tune-up process, but Step 1 results were not satisfactory. The fastest idle on each pot is achieved with airscrews only ½ turn out from “seated”. Normally they would be 1 ½ - 2 turns out.
Other observations: I had to turn the throttle stop screws up to get it to idle in the first place. And the float needles can stick open, requiring a sharp rap on the side of the float bowl with the handle of a screwdriver in order to stop fuel gushing everywhere.
I suspect that fuel gums may be blocking the pilot jet passages. I removed both carbs, cleaned out the float bowls, and blew out all passages using my air compressor.
It didn’t make any difference. Carbs are still not tunable at Step 1. I can turn the pilot airscrews in until they are seated, or out until they are actually removed, and the engine can still run on either one, or both, of the pots. This shouldn’t happen.
So next I suspected air manifold links. Who knew where my paranoia might end up? But spraying CRC onto the intake-stub joints didn’t make the slightest difference to the engine note as it idled.
This has me stumped. Maybe pilot air passages are still blocked, despite the compressed-air treatment? What do I do next? Try soaking carbs in some Space-Shuttle-type solvent?
