No, I hadn't considered the throttle shaft bushings. They seemed tight, but I suppose it could be the problem. Turtle, yes, sometimes it will come down if I give it a load, or if I shut it off, then right back on again while it's still turning, but not always.
It only rarely spits back, which seems to me more like a misfire, but it's rare.
I have read somewhere that enrichening the pilot screws might help this but I haven't tried that yet. Opinions on that?
