Technical Q and A for classic motorcycle maintenance and repair.
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.
Q: Why is my 2002 Triumph Bonneville so hard to start? If it has not been started for a few weeks, it is a gorilla to start. The carbs have been re-jetted to a 130 main, a 42 pilot jet, with the needles using two shims. I have replaced the spark plugs and charged the battery. What is the problem? — Rick Romanesque/via email
A: Your 2002 is different from the old Triumphs I’m used to working on, but since I recently had one the same age through my shop for a similar issue, I’ll take a shot at it. The one I worked on had sat for three years without being run, so the carbs were completely gummed up. But worst of all, and not found the first time, the petcock filters inside the tank had totally disintegrated, allowing all kinds of junk to come back in and clog the just-cleaned carburetors. Once the petcock was replaced and the carburetors cleaned (again), the bike started and ran as it was supposed to. So check your fuel flow through the petcock and the quality of the fuel flowing through the petcock, then make sure that all the carburetor passages are clean, including the fuel enricher/choke. MC