1973 20' SF - Engine Trouble?

[eggsuckindog]

Ok I have a solution maybe- none of us are Rude mechanics for 30 yrs I don't think. Call this guy Mike at American Marine and see if he can help you try some things- his number is 727 938 9796 and he is a past classic SeaCraft owner and his partner has a classic 23 but he knows more about Rudes than the bunch of us. Tell him you heard about him on here and I said to try and help you, he will. He can fix anything even on the phone, and you can tell him I said that too

[Bigshrimpin]

Eggs - unless he's a got some inhuman superpower . . . that motor cam't be fixed over the phone. It needs to be ripped down. That ring is either stuck or broken and the piston is painting the cylinder wall with aluminum.

[eggsuckindog]

Eggs - unless he's a got some inhuman superpower . . . that motor cam't be fixed over the phone. It needs to be ripped down. That ring is either stuck or broken and the piston is painting the cylinder wall with aluminum.

Didn't say he could fix it, just tell him what he's looking at when he takes the head off

[StrangeBrew]

Gents....Thanks for all the advice...Well, my mechanic pulled the head off and this is what's going on (as reported by my father):

"John removed the head and it appears the "o-ring" (this is the ring that seals the head to the block...60 degree V4's dont have head gaskets) is bad and water was leaking into the top section the cylinder in a small area about 3/4" long and 3/8" deep. I have cleaned up the surfaces of the head and the block and John is getting new "o-rings". I did another check after the head and block was cleaned. I raised the piston to the top position and using my feeler gauge stock I was able to insert .002" between the ring and the cylinder wall in two spots. It is strange since the area that was damaged from the water was tight and these two other areas where to the left and right of that section. I will lower the piston to the half way point in the morning and check it again in an area that was not damaged by the water. This is not good an would be the cause of the low compression. Not sure what can be done other than to remove the piston, hone the walls and insert new piston and rings. Will check with John in the morning once I learn more."

I think I will hone the wall of that cylinder, new piston, new piston rings and replace the "0-ring" between the head and block...What do you think?

[eggsuckindog]

The only problem with that is the labor to pull it down is the same if you did all the pistons.

[StrangeBrew]

I agree. I will do all of the piston rings while I'm at it.

[eggsuckindog]

I actually meant putting all new pistons and rings-you need to check that out - the labor pulling it down is the kicker. Then you would have a fully rebuilt engine, you would have to decide to keep it for awhile to make it work $ wise.

[Fr. Frank]

I actually meant putting all new pistons and rings...

Inspect the pistons carefully with micrometers. If they're in good shape, don't spend the extra $135 per piston to replace all of them. Just replace the damaged pistons or worn ones. Hone and re-ring the others. You'll undoubtedly have to replace the one, though. Don't be afraid to go one size over-sized on one cylinder if necessary.