Allright guys. Today I did some wrenching of my bike. Remember I had one cylinder and the airbox filled with gas for leaving the petcock on?
I was positive that the overflow tubes were clean. And they were... in the carburettor, but not the rubber ones.
I rebuilt my carburettors but didn't replace the bowl gaskets. Reinstalled everything, but the bowls leaked a little so I bought new ones. Put them without removing carburetors. There was some leaks here and there, but all small and they "cured".
I have removed the bowls today. First of all, let me tell you that the had lots of sediment. How can it be when the petcock filter is new, and also I cleaned it recently to discover more sediments there? You will tell me to install inline filters. I already did, but there is not enough tube lenght, and with them the gas tube was kinked so I removed them.
Back to the bowls. With spray carb cleaner I cleaned them inside and outside. overflow tubes were clean, but I gave them a blow. Then, with an air can, blowed the rubber tubes, and in two of them a dollop of crud jumped to the newspaper in the floor. It was not grease, as I know the grease I use and there was no reason for it to be there. It smelled like gas, but that's no wonder as by then all the garage smelled like gas. The only thing I can think of, is that it is indeed solified gas, as it had the same color as the stains in the outside of the bowls.
My theory is that, while riding, the gas inside the bowls moves, so always a little amount drains through the tube. That drops never fall off the rubber tube, because the tubes come down from the bowls to the engine case, then up to clear the swingarm and then down again to the plate where they are held in place. So the gas drops never get out of there unless a big overflow occurs, and even in that case some gas will remain (I hope you get the idea, like the water basin drain so there is always water on it to avoid smell coming from the sinks...)
That gas leaves a residue, and the next drop will add to it, and so and so until the rubber tube is blocked. So I rather modify the tube path so it drains direct, or remove them at all and leave the gas fall on the engine case.
Raul
