I actually regularly use the rtv silicone to make gaskets for the intake manifold and the cylinder gasket. I make sure not to glob it on and I always wipe the edges where it counts so nothing will get clogged. My advice to you would be to go through your fuel system again and replace the fuel lines, fuels filter, clean carburetor, draing and clean the fuel tank and clean or install a new spark plug. The fuel systems on these bikes are super finikey. The smallest thing will screw up everything. There is no fuel pump so you don't have to worry about that. It's a gravitational/vacuum operated fuel system. A word of advice is you can't clean these fuel systems enough, I've had to do this several times in order for some bikes to work properly.