Chris Hays
Petty Officer 3rd Class
- Joined
- Aug 14, 2007
- Messages
- 87
Rebuilding a boat i got which is a 1990 Glastron Sierra 175 with the 3.0l Mercruiser engine in it. The outdrive was shot so it had been sitting in the previous owners yard for a while. It seems that the boat was somewhat neglacted on the maintanence side of things so heres what happened. I noticed while removing exhaust riser from engine that the inside of the exhaust port area was rusty
, i put this down to a bad gasket between the riser and manifold. I removed the manifold and with a light, saw that #4 exhaust valve had a little surface rust on it. The spark plug told the same story but the other 3 were good. To be safe i pulled the head and found that there was about a 1" deep rust ring all around the cylinder bore at the top where the water had sat on the top ring, and another small ring around where it had sat on the oil control ring. It is slightly pitted as i can feel with my finger but i don't know how deep. What would your suggestions be as to how i should go about this issue, I have a finishing cylinder hone but i think it would take forever to rub out that mark. The rest of the engine is in EXTREMLY good shape and i suspect it has very little hours on it, as i can still clearly see the crosshatch oil retention marks in the cylinders and the pistons do not have any signs AT ALL, of glazing or wear on the skirts. Im planning on going back with new rod bearings, cylinder de-glaze and new rings on the #4 piston if i ever get this pitting out!! I hope i don't have to oversize it or sleeve it!!!
, i put this down to a bad gasket between the riser and manifold. I removed the manifold and with a light, saw that #4 exhaust valve had a little surface rust on it. The spark plug told the same story but the other 3 were good. To be safe i pulled the head and found that there was about a 1" deep rust ring all around the cylinder bore at the top where the water had sat on the top ring, and another small ring around where it had sat on the oil control ring. It is slightly pitted as i can feel with my finger but i don't know how deep. What would your suggestions be as to how i should go about this issue, I have a finishing cylinder hone but i think it would take forever to rub out that mark. The rest of the engine is in EXTREMLY good shape and i suspect it has very little hours on it, as i can still clearly see the crosshatch oil retention marks in the cylinders and the pistons do not have any signs AT ALL, of glazing or wear on the skirts. Im planning on going back with new rod bearings, cylinder de-glaze and new rings on the #4 piston if i ever get this pitting out!! I hope i don't have to oversize it or sleeve it!!!