A lot of the mods I'm doing are just about looks. For example, I'm going to powdercoat the carb top, float bowl and the round cover thing on the side. But I wondered what the round cover thing is, what's under it and what it does.
I checked the manual. Transient enrichment valve, huh? Looks like it moves in and out with the choke knob. Or should that be "transient enrichment knob?" Anyway, it looked like removing the cover was no big deal. Just watch for the spring.
Well, it wasn't pretty under there.
I couldn't help wondering how the sediment and debris would affect carb function. To be safe, I ordered a new diaphragm assembly.
Then I got wondering how many other people's fueling problems -- stumbling, backfire, stalling, etc. -- might be related to messed up transient enrichment valves, particularly if they've tried everything else.