1976 Suzuki GT750A Cylinder Problem


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, Motorcycle Classics, 1503 SW 42nd St., Topeka, KS 66609, or send an email with “Keith’s Garage” as the subject.

Ignition or carburetion?

Q: I have a question about my restored 1976 Suzuki GT750A. I did a complete engine overhaul on the bike, split the cases and had the crank rebuilt, including new oil seals. The CV carbs were also rebuilt. It has happened twice now during a ride that all of a sudden I lose power on one cylinder completely. It runs on only two cylinders for a bit and while I can keep the engine going on two cylinders and play with the throttle a bit all of a sudden it kicks back in and operates like nothing happened. Could this be an ignition issue or carb issue?

Jerry Gooren, Hayden, Idaho

A: Since it’s always the same cylinder, and the easiest thing to check would be ignition, I’d start like this: Rewire the coil from the constantly bad cylinder to one of the others, and swap that cylinder’s coil to the bad one. See if the problem migrates to the newly assigned cylinder. If so, you have a bad coil. If the problem remains with the original bad cylinder, then you should check that cylinder’s carburetor and mountings.

1/30/2020 1:06:29 PM

The same test can be done with the condensers. I would say very unlikely it would be an intermittent carb problem. About all that could be is a float valve sticking closed intermittently. Never saw that in 28 years as a MC tech, and countless carb rebuilds.

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