When adding power to a small engine via governor bypass or jet drilling, how much is too much? 

In the old days, Briggs 5 HP engine (diaphram carb), and Tecumseh, (all on mini bikes) we didn't re-jet anything when eliminating the governor..  Never blew up an engine (limited WOT).
 
I would try W/O any jetting mods but check the spark plug color after a full, wide open pass.  
I suspect it'd be ok..
 
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