Hello all, I am in the middle of rebuilding my Keihin FCR-MX 39, The original problem that led to a carb rebuild was my bike did not want to start very well or Idle after it was started. it would only run with the cold start on or the throttle opened off idle. I fixed this problem before by removing all the jets for inspection and cleaning them. usually it was the Idle jet that had debris in it. This time all the rubber parts had started to fall apart. pilot screw o-ring gone. Accel pump diapham almost gone. ect.... I think the 10% ethanol in the pump gas is a big factor. I kept finding bits of rubber after all was dissasembled, so I dissasembled the fuel block from the main body and the was more rubber o-rings falling apart. Now to the question. These orings are not available for service from keihin. They require you to buy a whole main body. I was going to try a anarobic fuel resistant make-a-gasket sealer. I was going to use a hyperdermic needle filled with the sealer to fill these very tiny o-ring grooves. Has any body run into this and have another idea? My other options at this point are, but I want to try fix this one. 1. ebay-used carb 2. Edelbrock carb 3. New carb 4. New main body Thanks for your input!