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Tech Corner

Technical Q and A for classic motorcycle maintenance and repair.

Leaking Tank: 1970 Norton Commando

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.

Leaking tank

Q: I have a 1970 Norton Commando with a fiberglass tank. It is leaking again after sealing the tank a couple of years ago. Do you have any suggestions other than purchasing a new steel tank?

A: Unfortunately, I don’t have any easy fixes to offer. Once the alcohol has found its way under the liner, it will continue to work on dissolving the fiberglass resin. If the liner is Kreem or something similar, it may be possible to dissolve it with MEK (methyl ethyl ketone) and then attempt to reline with a novolac epoxy liner such as Caswell. But even then, there is no guarantee the fiberglass will remain intact. Inexpensive steel tanks are available from India, but reports have been mixed as to quality. There are some modern fiberglass tanks out there that claim alcohol resistance, but I’m still not convinced a fiberglass tank is a safe option. MC