Motorcycle Repair: Yamaha pw 80 bogs at high speed, air fuel mixture, yamaha pw 80

Question
Bogs out, changed spark plug, removed exhaust still the same, has good compression , could it be the reed valves  it is a 1996, starts an idles fine  

Answer
Hi Jon,

You're killing me, Sir. : ) Please follow my instructions for posting a question.

Can you provide more detailed information on the symptoms, and any history of repairs, modifications, description of the old spark plug, riders riding habits? What is the compression readings?

Otherwise, your answer is: the air-fuel mixture is too rich. Carburetor needs tuned and/or cleaned, also air filter may too restrictive.

Respectfully,
Mark Shively