When I start my VFR400 NC24, gas leaks under the bike and it is coming from one of the Exhaust pipes. When I rev up the engine, it stops. When I start using it, the leak doesn't show up. It only leaks, when I start it from cold. I already made an oil change because gas has already mixed itself with the engine oil. I already brought it to a mechanic, they sync the carbs and fixed #4 valve. But when I got home, the leak started again. What seems to be the problem? Need Help...
Check the carb.floats if stuck, etc. check the float bowl gaskets if leaking. Hard to say really not familar with your motor, but unburned fuel going into cylinders and not firing check if sparkplugs are all firing also could be carb floats or piston rings, do a compression test also, are all cylinders hot to the touch when it was running and if running did it run smooth? If the fuel is mixing with the oil then you have some big time problems and need to fix it before you ride it again!!!
