Clean the Valva and it should solve the problem.
Take off the air filter box lid.
Remove the air filter box along with the filter.
Remove air hose which is attached to intake / throttle body.
Remove th valve....note..the phillips head screws are easy to strip so make sure you have the proper size phillips head screw driver.
Clean enitre valve thoroughly with throttle body / carb cleaner.
Re-assemble, and this should help eliminate the problem. If not, check for fouled plugs, stretched line from accelerator to throttle control, or fouled coils.
