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 e-mail with “Keith’s Garage” as the subject.
Q: I have just acquired a 1976 Suzuki TC185. The bike starts easily and runs, but has some minor problems. It has a 71.5 main jet, but my manual says it needs a 130 main, so now I doubt any of the jets are correct. What is the correct carburetor setup for this TC185? I can’t find any information, much less the parts. So far I’ve cleaned the carb, the air filter, the gas tank and the spark arrestor. I’ve replaced all the fuel lines and added an inline filter and a new spark plug. As I said, it starts and idles but then gets blubbery, like it’s holding back. I think my top speed might be 30mph with the throttle wide open. I’ve tried the dual-range transmission and that works fine. My problem is in the carburetor, but I need to know what the right jets should be and where to get them.
— Dean/via email
A: That’s a sweet little scrambler you found. That main jet size is correct for the 185 twin, but not the single. The main jet should be 130, as you found out. The pilot or idle jet for that model should be 17.5. You need standard Mikuni jets. If you have a local motorcycle shop that’s been in business a few years, they may have what you need on hand. If not, Dime City Cycles has the jets. Just search on their site for those jet sizes.