A little tuning help, please?

[Loudo]

My '63 CB77 generally runs great. Fires right up, idles perfectly, proceeds nicely. The only fly in the ointment is during acceleration. If I accelerate gradually there's no problem. But if I give the throttle full twist at low revs in second or third gear, it wants to bog and pop back through the carb. This is especially true when under load on hills. Does someone have an opinion about whether I should be looking in the direction of ignition timing or the carbs?

[davomoto]

I don't know that you will be able to tune this problem away.The engine can only ingest so much fuel and air at a given RPM. My YZ250 has an accelerator pump which helps greatly for those situations, but it will do the same thing if RPMs are too low, and throttle is wacked too hard.

davomoto

[Loudo]

Thanks, davomoto...would it be safe to assume that you're saying this is a normal condition for good-running 305 engine and that one just needs to ride accordingly?

[davomoto]

Without being able to ride the bike myself, it sounds pretty normal. Have you checked th color of the plugs to inure mixture is correct?

davomoto

[DONZIE]

Sounds like you could be running a bit lean to me. Try raising the needles up one notch in the slides.

[Loudo]

Donzie, you hit the nail on the head. I moved the clips on the jet needles from the middle notch to the next notch down. Much, much better. Doesn't want to convulse anymore and I don't have to baby the throttle now.

Thanks, Donzie!

[DONZIE]

WHEELIE TIME !!