I was racing a GP a couple of weeks ago and the course had a 1/4 mile drag strip connecting the off-road section to the MX tracks. I was racing so I just held the bike WFO all five laps. On the fifth lap the bike started makin a squeeking, scratching noise so I figured I damaged something in the top end.
I pulled her apart and found no smoking gun, no piston damage, cylenter looked like new, etc., but I replaced the poston,rings, wrist pin, top bearing and all gaskets since I had about 8 races on it and I was there.
I ran two 40 mile races after breaking in the bike per the service manual and everything seemed back to normal.
Sunday I was racing a qualifier and about two miles into it the race the noise started again. It seemed like I lost my low end power and at one point it stopped running...I thought it was siezed, but it was not. I restarted the bike and finished the first loop (32 miles). The bike ran fine, except I noticed a slight degrade in lower end power, that I thought was friction, but now I don't.
I wanted my points so after a quick samich I decide to ride the second loop (42miles). The noise went away and stayed away for the last 20 miles, and the low wnd power was back to normal. This low end power observation was very very slight.
I am thinking there is something wrong in the power-valve system...Any suggestions???
I pulled her apart and found no smoking gun, no piston damage, cylenter looked like new, etc., but I replaced the poston,rings, wrist pin, top bearing and all gaskets since I had about 8 races on it and I was there.
I ran two 40 mile races after breaking in the bike per the service manual and everything seemed back to normal.
Sunday I was racing a qualifier and about two miles into it the race the noise started again. It seemed like I lost my low end power and at one point it stopped running...I thought it was siezed, but it was not. I restarted the bike and finished the first loop (32 miles). The bike ran fine, except I noticed a slight degrade in lower end power, that I thought was friction, but now I don't.
I wanted my points so after a quick samich I decide to ride the second loop (42miles). The noise went away and stayed away for the last 20 miles, and the low wnd power was back to normal. This low end power observation was very very slight.
I am thinking there is something wrong in the power-valve system...Any suggestions???