Im running a vm 18 i tried the 70 jet it does ok at times at t wot but then 4 strokes at 7400 Rpms at times it does great though.so i dropped to 65a.n still it does same thing at times.I've looked for air leaks.changed gasketsshould i go to a 60 or less.keep in mind it wasn't doing this before.i have noticed that the rubber o ringed gromit inside carb that the intake slides into is tore some.not the round white one that carb clamps to. Is there something Im missing not had much experience with the clamp on type carb on my cr machine motor it has the 21 phgb spigot mount it gives no problems.but i like this mikuni its great for my little streamers anyway what should i do please help