1972 Triumph T100 Valve Issues

| 1/27/2016 12:30:00 AM

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.

Valve issues

Q: I have a 1972 Triumph T100. While riding, an exhaust rockerbox cap came off and the adjusting pin and lock nut came off also. I probably rode it a couple of miles home with it just running on one cylinder. I replaced all four adjusting pins and lock nuts, and set the valves correctly. The bike started on the first kick and sounded good in the garage, but when I tried to take off, it has no power. I will readjust the valves, but I suspect a burned valve. What do you think? Doug/via email

A: Burned valves usually result from valve clearances being too tight, keeping the valve off its seat, where the heat gets transferred from the valve to the cylinder head. In your case, the clearances were too loose, so the valve didn’t lift at all. You didn’t say whether it was an intake or exhaust valve that the adjuster fell off of, but it shouldn’t really matter in this situation. Check your compression, and if possible do a leak-down test. That should give you more info about the condition of your engine. It’s possible that there is some carbon buildup on a valve stem or seat that is keeping it from closing fully. That would also affect power output.

The sound and the fury: celebrate the machines that changed the world!

Motorcycle Classics JulAug 16Motorcycle Classics is America's premier magazine for collectors and enthusiasts, dreamers and restorers, newcomers and life long motorheads who love the sound and the beauty of classic bikes. Every issue  delivers exciting and evocative articles and photographs of the most brilliant, unusual and popular motorcycles ever made!

Save Even More Money with our RALLY-RATE plan!

Pay now with a credit card and take advantage of our RALLY-RATE automatic renewal savings plan. You save an additional $5.00 and get 6 issues of Motorcycle Classics for only $29.95 (USA only).

Or, Bill Me Later and I'll pay just $34.95 for a one year subscription!

Facebook Pinterest Instagram YouTube Twitter