Motorcycle Questions? Ask a Mechanic.
Hello how are you today? I do not have a whole lot of experience with this particular model I can offer you at least one suggestion. If memory serves me the fuel tank is lower then the carb, this means the atv has a fuel pump. Check the vacuum line from the intake to the pump, when the diaphragm in the pump goes bad it will allow excess fuel to enter the intake. Pull that line while the engine is running, it should be completely dry.
Pinch the fuel line while its running and see if it clears out. do you have any blow back into the intake?
If the intake valve clearance is not tight, next step would be a leak down test. Here is a link for more info about the test. It will tell us if compression is leaking back into the intake.
Where is it leaking from?
Is the intake boot rubber? I can not tell from the parts diagram.