Briggs & Stratton 25 HP Intek Engine "Racing"
My 25 HP Intek Twin Model 445777 Type 0134 engine with 47 hours, clean gas, oil and filters, started "racing," after one hour of mowing this week, blowing smoke. I've mowed three times this season; over one hour each with no problem. Choke now runs in "reverse," meaning that I have to push it all the way open to slow down engine, throttle handle appears not to slow or speed up engine. Engine "racing" at about twice normal RPM. Carburetor appears to be OK; throttle and choke plates move freely; no apparent dirt or blockage, no missing linkage. If I put my hand over the air intake to the carburetor, it slows down engine. When I remove my hand, it resumes "racing." Tractor is John Deere L2548. Could it be the Governor and how would I test? Any other ideas? Thanks.