Tuesday, 29 June 2010
Spent yesterday evening stripping the bike down to once again try and find my problem. Troubleshooting was helped by a trail of small pieces of metal, both in the crankcase and in the rotary valve cover..... leading eventually to the culprit, which was a completely destroyed small end bearing! The bearing was sucked around the crankshaft and partly spat out through the rotary valve, damaging the disk, and covers on the way, and also taking a trip up and down with the piston a few thousand times.... Pictures speak louder than words.
So was this the cause or another symptom.... I'll have to spend some time to think about that one.
I have sent the barrel and head back to Performance Fabrications to have a hone, and fix up the head which had been "bead blasted" by loads of little bits.... A new piston and rotary disk are ordered.