Bonneville America Forums Forums Technical Forums General Tech Hesistation at 1/4 throttle

My bike tends to hesitate at about 1/4 throttle. It's no so bad once it gets warmed up, but for the first couple of miles, and especially on cooler days, it's quite noticeable.

My next mod is probably going to be a Procom ICU. Will this help the problem, or is it likely to be something more basic like the needles?

too lean ...had similar problem recently....

Thanks, Grzegorz! I've been meaning to balance and tweak the carbs soon anyway.

Agree with Gregorz because it gets better when warmed up. Have you tried running with the choke pulled to see if the hesitation goes away?

Correct me if I'm wrong, but what's the point with the choke if not to richen the mix a little bit while the bike is cold? But does that mean you are lean when the bike is at operating temperatures?

If you're jetting so that you're perfect when you're cold, won't that make you rich when the bike is hot, like driving with the choke on permanently?

You are right regarding setting the bike up for warm running. An engine should be set up with the proper air/fuel ratio for warm running and at your typical altitude above sea level. Cold engine running is covered with the choke or enrighener. Most bikes, when they are set up for normal running will run somewhat ok when cold. If they hesitate, it is usually an indication that the bike is too lean in general. Pulling the choke, cold or hot, and eliminating the hesitation confirms a lean condition.

Get that?

Jebus…

Yes I did. Was just asking…

I do appreciate the explanation, as I am but a mere acolyte in the eldrich mysteries of carb tuning.

I always figured the choke was more or less just to get you started. That you should be pushing in the choke just after, or very shortly after starting, not after a couple of miles.

But in any case, the hesitation is noticeable even when the bike is warm. It's just VERY noticeable when the bike is cold.