Earlier this summer I had the boat out and suffered what seemed at the time to be fuel starvation. Changed the fuel filter and managed to get the boat back to the harbor by manipulating the carb linkage to keep the motor from stalling when shifting into gear. Along the way there was another "starvation" episode, and at least one occasion of bad mechanical bang from the motor. When back, I pulled the carb to bring home. The carb was NOS self-installed at the end of last season, after which the boat ran nicely for several trips.
Today I went back to check a few things and started with a compression test (motor cold, carb off, plugs out).
1- 140
2- 35; goes to 50 after squirting oil in
3- 110; goes to 140 w/oil
4- 122
5-124
6- 150
The #3 cylinder has been low for ages, since not long after the rebuild. I last checked compression earlier this season, and the #2 cylinder was in line with the rest. Motor is a GM 230 Merc block bored to 250, rebuilt 1100 hrs ago. The boat is a '72 Sportcraft 22, but has a nice Alpha One outdrive adapted to it. Otherwise there's little value to the boat except that it runs and floats.
I'm debating what to do now. I did the oil test on #2 three times - how strong of an indication is this that the problem may be with the head and not the rings? There are no out-of-place noises when spinning the motor, and the plugs all look the same. It's not worth it to me to have the boat fixed by a shop, or to drop in another engine, but if I can pull the head and have it rebuilt or replaced, I'd do that. It would be worth $500 to get another season out of it before moving on to something else.
The alternative is stripping and junking the hull, or selling it as is. I could probably get $1500-$2000 for the trailer, motor, outdrive, and a few of the other fixtures. I doubt I could recoup more than another $1500 tops even with a fresh motor, and as is I think I'd struggle to match the part-out price.
Today I went back to check a few things and started with a compression test (motor cold, carb off, plugs out).
1- 140
2- 35; goes to 50 after squirting oil in
3- 110; goes to 140 w/oil
4- 122
5-124
6- 150
The #3 cylinder has been low for ages, since not long after the rebuild. I last checked compression earlier this season, and the #2 cylinder was in line with the rest. Motor is a GM 230 Merc block bored to 250, rebuilt 1100 hrs ago. The boat is a '72 Sportcraft 22, but has a nice Alpha One outdrive adapted to it. Otherwise there's little value to the boat except that it runs and floats.
I'm debating what to do now. I did the oil test on #2 three times - how strong of an indication is this that the problem may be with the head and not the rings? There are no out-of-place noises when spinning the motor, and the plugs all look the same. It's not worth it to me to have the boat fixed by a shop, or to drop in another engine, but if I can pull the head and have it rebuilt or replaced, I'd do that. It would be worth $500 to get another season out of it before moving on to something else.
The alternative is stripping and junking the hull, or selling it as is. I could probably get $1500-$2000 for the trailer, motor, outdrive, and a few of the other fixtures. I doubt I could recoup more than another $1500 tops even with a fresh motor, and as is I think I'd struggle to match the part-out price.