Air leak on motor

I need your guys help finding a air leak on my new 66cc! I've Been riding my new MB build for a couple of days now,I hear a whistling sound coming from somewhere on the engine while going about 15 mph.When I first got the motor the seal on the crank shaft where the case splits,a hairline piece of gasket was missing so I used a bit of RTV Silicone on there.I haven't tried carb cleaner to check for air leaks yet and don't plan to as it would remove the paint on my motor..What do you guys suggest I do/check here? I'd appreciate any advise thanks!

I'll probably try some brake cleaner maybe WD-40 tomorrow,if anything I'd rather not have another mess to clean up lol.The weird thing here is the motor starts right up with half choke and shuts off if push it to full choke.I would think if the motor didn't shut down at full choke there would have to be an air leak somewhere.

fairracing31 said:

Sometimes those whistling sounds are the clutch, also I had one where I could not find where the sound was coming from.

Turns out is was my air cleaner cover. If you have the old style round air cleaner cover pull it off and take it for a spin. If the whistling goes away, cut some notches between the inlet holes on the cover. Some have a weird way of turning into a musical instrument.

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I'll watch the clutch for the noises now.I drilled about 4 holes in the top part air cleaner cover today,took my bike for ride and didn't notice any performance gains or anything different.So tomorrow I'll try what ya mentioned and see if that's it.

I've been pondering around here finally got to the gas cap mod of yours,I drilled 3 holes in the lip and it did help out a lot! Thanks much Fair I think I'll just wait to pull the motor off when Manic motor mount gets here this week.I'll then seal everything up,port match and give the motor some good maintenance.