rotary valve just exploded...

[tesoriero93]

Just turned it on, gave it a rev and then heard high pitched grinding. Opened the valve plate cover to find the plate bent and stuck on one of the ports. Anybody know what could have caused this?

 

[jjsinaz]

My guess would be that it ingested some type of foreign object (carb screw or similar)

 

[mikidymac]

I have also seen the piston pin bearings cause that when they let go.