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Tech Corner

Technical Q and A for classic motorcycle maintenance and repair.

Using Lead Additives in a Triumph TR6

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.

Using lead additives

Q: Should I use a lead additive in my 1970 Triumph TR6? Chances are the head has never been off. Also, can you explain to me how the choke system works on this bike? It won’t run when I pull the lever toward me. It only runs when the lever is away from me.

A: Most of the information I’ve read states that in normal use, other additives in gasoline provide the same protection that lead used to provide. During the initial switch from leaded to unleaded gasoline, there was concern that rapid valve seat wear would occur without the lubricating effect tetraethyl lead provided. Hardened valve seats were to be the solution. Experience has shown that the concern was unfounded except in the case of engines that were run very hard, i.e., racing engines. On your choke issue, the Amal chokes are off when the cable is tight and on when loose. MC