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Tech Corner

Technical Q and A for classic motorcycle maintenance and repair.


Carburetor Floats: Honda CB1100F

Motorcycle Classics tech expert Keith Fellenstein

Editor’s note: If you’re having trouble with that old Suzuki, BSA or BMW, Keith Fellenstein is your guy. From motorcycle tuning tips to detailed motorcycle engine repair, he can draw from a wealth of experience to help guide you to success. Send questions to: Keith’s Garage, 1503 SW 42nd St., Topeka, KS 66609, or send an e-mail with “Keith’s Garage” as the subject.

Carburetor floats

Q: I have a 1983 Honda CB1100F. The carburetors are overflowing. I have replaced the float needles. I was told the floats were white when new; they are now dark brown. If I replace them will it cure my carb problem? The floats are $65 each, and I wanted a second opinion before I spend that much money. — Mike Gregg/via email

A: Without seeing the floats, I can only guess as to their condition. It depends on the type of float you have. Are they hollow or solid? If they are hollow, the color of your carburetor floats has no effect on how well they work. The important consideration for hollow floats is whether or not they are still sealed, with no fuel inside them weighing them down, which would cause overflowing. If they are sealed, then they should still be working as designed. If the floats are a solid foam type, it’s hard to tell if they are still good without a new set to test against. If you have a new set to test against you can try floating both sets in gasoline and seeing if they both bob to the same height or if the older set sits lower in the fluid. MC