Honda GC190A-E1 timing belt or governor ?

[Rpmp3]

Honda GC190A-E1 187cm3 eng. family G20D54S0160J1A owner said started to backfire & pop, found piston TDC , cam out of time, removed belt spun cam for defects did not find, set cam to specs put timing belt on & put together. fired right up but took off racing past normal RPM quickly shut down, did a governor check loosen nut held lever back turned governor shaft clockwise locked governor down tried to start not a pop, back to square 1, valve cover off cam out of time.I believe the timing belt is worn thus causing timing issues but what caused it to race past a normal operating range

[Skywatcher]

Hi RpmP3

Honda says to change the timing belt at 400 hours running time. If timing gets too far out, piston will strike a valve and bend a rocker. Also check to see that the rocker cover hasn't been replaced with the wrong cover. Rocker covers for GC engines have a belt guide spot welded to the inside to keep the belt on the cam wheel, whereas GCV engines rely on gravity to keep the belt on track.

When synchronizing governor shaft to throttle shaft, set the throttle control to full throttle to put maximum tension on the governor spring. Loosen the governor arm on the governor shaft and make sure the throttle shaft arm is touching the full throttle stop. Turn the governor shaft the same direction as the governor spring is pulling the governor arm as far as it will go and tighten the clamping nut. All the best,

Sky