After this little run the engine was noted to feel stiff on the down stroke, so it was torn down to confirm the cause
Engine Disassembled after run on 1/3 part blend diesel fuel, note the aluminium sleeve force fitted over cylinder
Piston protruding from cylinder, note thick wall at wrist pin location
Crank shaft with noticeably bent web which caused binding on the down stroke
A quick fix temporary repair was accomplished by clamping one end of the web in a vice and straightening the bend with a pair of pliers.