after nearly 4000km my favorite bike died on me, severe loss of compression.
back home i took the engine apart, the inletvalve wouldn't close and there was lots of play,2mm, between rocker and valve.
removed the valves (are those valvesprings strong!) and saw that the valveseat had lifted and it was sitting at an angle;
the valveguide on the exhaust was loose, one tap with my hammer and the guide was out.I measured the bore and piston, as good as new.
I would like to doubleplug the head and put 8mm valves and guides in;
What is the best adress to repair the head or find the right parts ( oversize 8mm valveguides)
I removed the right side cover and noticed that the end of the crankshaft was badly grooved, the plan was to use oilseals instead of the alu bush in the oilfeed to the crankshaft.
The bike has only done 23000km?
please HELP
marc