Out for a test of the Mono today and came across this in my local repair shop! Apparently the owner was happily cruising at ~50mph when he "lost all power"!
The bike appears in good condition and has only covered ~12,000 miles.
The head of the exhaust valve has sheared off at the base of the head, then been jammed between the top of the piston and the head multiple times. A lot of the shrapnel has apparently disappeared up the exhaust port and into the silencer!
Whilst the top of the barrel has a few nicks on the top edge of the bore, it has little damage. Not sure if the rod has been bent, but one of the push rods is bent as well as this damage in the images.
How much will require renewal has yet to be ascertained, but if it were mine, the crank would be out for a clean and check along with all the bearings replaced, plus everything above the crankcase!
No cheap!
Just be aware that exhaust valve heads on Enfield 535 motors may drop off!!!
My regards, Bill
