Well I tore into the engine this afternoon. There was a heap of sludge in the bottom of the crank case, mainly cloging up the oil drain plug holes. The valves and piston had reasonable amount of carbon buildup on them. This has all been cleaned off, the rings still have a servicable gap on them, so no need to try and find new ones. The piston looks really nice now, I couldn't resist and polished to top of it...
[Linked Image from i27.photobucket.com]

Next up will be to lap the valves into their seats, the inlet looks fairly good already, but the exhaust does need a bit a attension.


I am now in a bit of an undecided state of mind... Do I strip the whole thing and try to restore it all to as new condition, or just service what needs to be serviced and leave the rest as is... I think I'm leaning towards the later as I do plan on using the mower, not putting it on show. And if I do a full resto, I'll end up being worried about using it in case I scratch it.