Older Briggs & Stratton 18 hp L head engine kicking back & destroying starter pinion

[heritage13]

Older Briggs & Stratton 18 hp L head engine kicking back & destroying starter pinion

I have an older Briggs & Stratton L-head 18 hp engine. Lately, it is kicking back and destroying the starter pinion gears (i.e. 2 in the last month). I have checked the valve clearance and both valves on both pistons checks to be in spec (i.e. .003 & .005 intake & exhaust respectively). This engine does not appear to have a compression release mechanism on the camshaft. Does anyone have any idea what might be the issue?

 

[Winmac]

If is kicking back hard it could have sheared the flywheel key, or if it has points they could be way out either or will throw off the ignition timing.

I got the same engine on a welder and for awhile it was eating the gear too, it wasn't really kicking back but just not starting right. The carb was the issue after trying every possible adjustment I gave up and replaced it, it's been a few years and it hasn't destroyed a gear since, in fact there is a spare zip tied onto the shroud that hopefully I'll never need.