East Fortune September 05

Bike has had the modified heads and flat top pistons since the last outing (Croft Oct 04, no diary)
Weather Sat moring was dry to start the showery as the day went on.
Prior to first practice there was some very light rain though not enough to leave water on the track.
Went out on slicks (old front, new medium rear). Track was slippy so I took it fairly gently. I was feeling rusty and my riding was a bit coarse.
Completed about 10 laps of running in. Bike seemed to be pulling OK, nothing out of the ordinary seemed to be going on.
I did notice that the temp gauge seemed a little eratic when I came in and I decided to try and make an effort to monitor it next practice.
I did not check anything at the moment, rather decided to do it after the next practice when I had given the motor its head. This was a big mistake and next time full checks should be done after the first run.
The weather deteriorated for second practice and spray was noted coming from the bikes on track, so I switched over to wets.
First lap or so was fine, then as I came through Hannahs I was a gear to low and the engine bogged and one cylinder took till near railway to pick up. It was still not right and I decided on a plug chop and come in to see what was happening.
The R/H plug came out with alloy on it and the L/H one was loose and the electrode was gone. The L/H head was also cracked along where it had been previously repaired. Engine did not want to turn over by hand and there was no coolant left.
Removed barrels and found R/H to have seized on exhaust side and melted piston crown. Piston also appeared to have been touching head. L/H piston had also been touching head and was also marked as if a bearing had let go.
Rebuilt top end with old standard pistons and heads and spare R/H barrel.
Got bike rebuilt in time for the first race (just). The track was still wet so went out on wets.
Got a fairly pisshy start and was content to follow round for a couple of laps till I got a feel of things.
Bike was running nicely and after a few laps I started to work my way past people.
Coming out of the Snake I felt some harshness in the transmission, a bit like the sprocket/swingarm problem. However down the straight and through the esses it smoothed out, so I continued on. Through Hannahs however, I missed a gear and there was a bang from the 'box. I tried to get it back in gear again, but it would not select so I was forced to retire at Pates.
Back at the pits, when we removed the bellypan there were bits of casing and gear in it. On inspection I found a hole above the front sprocket.
Willie Paterson explained that failure of that gear usually occured when the bearing behind the sprocket colapsed. This would account for the harshness felt at the Snake. To be confirmed on removal of the 'box.

On removal of the 'box however I found all the bearings intact, so it would appear that the gear has colapsed as a result of wear and tear.

The remains of second gear.

2nd gear exit hole.