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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

jhutbeer
4/3/2014 1:29:17 AM

I got my 1974 Norton Commando 850 Roadster tank from India, and I am very happy with it. This finish is excellent. I did use the gas cap that came with it, but I didn't like the style of the petcocks, so I switched them with ones I already had. The only downside I found with the tank is that it appears to use the older Non-Catalyzed single-stage paint. The inside edge of the filler tube where the gas cap goes has had the paint wrinkle. This does not show once the gas cap is closed. To be sure I put excellent wax on my tank to protect it from any future gasoline spills. So far the tank is just perfect, and looks great! My original Norton tank also had a problem with gasoline lifting the paint where the petcocks leaked gas.