Neil Sinclair
2004-11-17T15:50:00Z
I pass this on for those Seal28-ers still using the Bukh engine. Last season, my DV20 sprang an oil leak from the aft side of the cylinder head gasket. I have found that the leak was due to a stuck breather valve. I didn't know such a thing existed, but you find it underneath the rocker cover. It looks like an inverted funnel with a pipe connecting it to the inlet manifold. The idea is that it scavenges the exhaust gasses that leak past the pistons. It contains a simple one-way valve to stop oil from getting into the inlet manifold. If the valve sticks closed, then pressure builds up inside the engine and voila - oil leaks. You need to unscrew it and wash it out in petrol. Be careful not to lose the tiny oil seal sleeved onto the pipe!

Neil
Neil Sinclair
Neil Sinclair
Seal 28/27
'Andiamo of Exe'