Which gasket are you talking about, the one between the pump and the engine block, or the one for the glass filter dome on the pump? Neither one needs any sealer at all. By introducing sealer into the mix you're more likely to create a leak, not prevent one. The pump-to-block gasket won't leak gas anyway- - - -it's there to seal oil. Use a little brush-on Permatex if it makes you feel better, but it isn't necessary as long as the sealing surfaces are clean. The cork gasket for the sight glass doesn't need any sealer, and definitely don't use some sort of rubber-base stuff like RTV! Any residue will end up in the carburetor, clogging up jets and/or causing flooding.
Jerry
