Need help from the small engine gods

[Slick 55]

When I used to build engines for WKA karts (5hp Briggs and Stratton) I never used flywheel keys since I set the timing with a degree wheel. I would take a small amount of valve lapping compound and lap the flywheel to the crank. I would then clean both completely with brake parts cleaner. I never had a flywheel jump in 11 years (some engines turned 8,800 rpms +).

 

[Car Luver]

thanks for all the info. Found out the output shaft bolt was loose. tightened it up and and adjusted the
mixture and now she runs like a champ!!