30-03-17, 10:07 AM
OK, I checked the valve seals this morning by carefully filling the combustion chambers with engine coolant and blowing compressed air back up the inlet and exhaust ports (I used an old plastic bottle lid with a hole drilled in it to seal the outside of the port).
First prize goes to......Disorderlypunk! Both inlet valves on cylinder one are leaking.
Second prize goes to....Fazerider. The exhaust valves on cylinder one are also leaking slightly.
Of course none of the above explains the compression readings, which were ok on cylinder one and low on cylinder two. It's possible that there might also have been a slight leak in the gasket, but recent enough not to do any obvious burning damage to the head or block mating surfaces. Since the gasket's going to need to be replaced anyway I guess this doesn't much matter.
On the bright side, the allegedly low mileage engine which I bought off ebay is clearly otherwise in very good nick. There's still clear cross-hatching on the cylinder walls and the heads and pistons are very clean.
Hopefully the valves don't need anything more than lapping in.
First prize goes to......Disorderlypunk! Both inlet valves on cylinder one are leaking.
Second prize goes to....Fazerider. The exhaust valves on cylinder one are also leaking slightly.
Of course none of the above explains the compression readings, which were ok on cylinder one and low on cylinder two. It's possible that there might also have been a slight leak in the gasket, but recent enough not to do any obvious burning damage to the head or block mating surfaces. Since the gasket's going to need to be replaced anyway I guess this doesn't much matter.
On the bright side, the allegedly low mileage engine which I bought off ebay is clearly otherwise in very good nick. There's still clear cross-hatching on the cylinder walls and the heads and pistons are very clean.
Hopefully the valves don't need anything more than lapping in.