So in the beginning of the summer during first ride, after 80 km i lost charging. No power from stator. Afterwards at home had trouble with finding neutral. Had to open the engine and turned out there was a washer loose, from a shaft in the left side. When all conditions were right, it finally got stuck to the magnet and sliced the wires when rotating. That´s a 30 eur easy fix. Found a crack in the skirt of the piston and since the cylinder was very slightly oval (can only be determined when using the right cylinder measuring tool), ordered 100.25 piston and had the cylinder rebored. Also installed a new gear lever shaft, while i was at it and the engine was in half. Got my neutral back aswell. Ordered a complete seal set.
Had no trouble opening the engine, bolts were ok. Still, broke 2 of the the rotating clutch centre´s bolt sockets. New used one from Gremany cost 40 eur. Note to other people - if you don´t have the right tool, don´t try to open it with a regular wrench, only air gun. There are some tricks you can use, but either way it´s reasonable to use air gun since you also have to open the crankshaft bolt and nut, 125 nm and 110 nm. Much safer with air gun. Engine in half:
Rebored:
Self made tool for valve stem seals. Works fine but it´s easier when a friend can hold the head, i did it alone:
Changing the valve stem seals:
This is the clutch centre holder. Can be done without it but it´s much safer and easier if you have one to use:
So next, attach the head, time the cam, wait for stator to arrive from shop and close it up:
All in all, be careful what you wish for. During winter/spring i was thinking i should get a thumper engine from somewhere to rebuild it, just for fun and experience. Had to rebuild mine instead. Still, can surely recommend the job for anyone interested. It´s a fairly simple engine and once you quit bitching about it, it´s a fun thing to do. If you lack time, it´s better to take it to a shop instead. Also, if you just want to rebore it and install a new piston, this can be done while the engine is attached.