
Expecting the worst, I was pleasantly surprised to find that due to a previous engine problem (broken rings breaking through the ring lands on the piston or broken valve edges),
new valves had been fitted and a new piston in the not too distant past. The valve guides are also in good shape but the exhaust valve seat has been re-cut beyond the wear limit and really needs to be replaced - the factory wear limit is reached when the head of the valve (fully seated) is 3.5mm below the surface of the cylinder head and I reckon this one is down by 7mm or so.
If I have a new seat fitted then I can have the impact damage voids repaired by welding and then refacing the entire sealing and combustion face.

The engine is now much more dismantled than I originally thought necessary but the outlook is good.
Chris

