sounds very strange. Why not just get a new gas cap? I would try soaking in rust remover or something, just make sure it doesnt eat away rubber
@FastCletus552 aka Jimmy C, buildin' rides out of Napa CA
Current Build 1980 CB 750 F
Finished Build 1975 CB 500T Cafe Racer - SOLD
2002 Ducati 998 Biposto
2005 Rossi #46 Scooter