I didn't get too far with this project before I have a question. 1954 10hp with unknown history. Ran when parked 10+ years ago. Looking to get it running to use, so plan on a complete tuneup with new coils, points, carb kit , water pump, fuel pump mod etc.
First thing, checked the compression to see if it was a viable candidate. Top cylinder 75, bottom 15. Sprayed more oil in the plug hole, now I have zippo for compression. Hmmm, not good.
May as well pull the head and see what I see. Expecting burned piston or badly scored cylinder. It all looks OK to me, but the head gasket looks very suspicious. As circled in the picture, there is a section that looks blown out to me. Also some blackness on the cylinder top surface and some darkness in the water jacket. Suspecting the head gasket is blown and was going last time it was running. Sitting for 10 more years didn't help it. Head bolts were fairly snug all the way out as if they had not been turned in 55 years, so guessing it may be original. Maybe not, but the gasket is OLD. It is making pressure in the crankcase when I turn it over as I get a little puff in the cylinder when I turn it over with the head off. Cylinder walls feel OK, the picture makes it look worse than what I can feel. Actually, the bottom cylinder looks a bit better to me than the top that had decent compression. Seems like the proper amount of play in the piston at the top, not too sloppy, not too tight. All in all seems to me like it should have compression with a new gasket. But, this is the first outboard motor I have ever taken apart, so I wanted to get a second or third opinion before I dump money into it. ($200 or so in parts for everything, well worth it if it's a runner, not so much if it needs more.)
One last question. When installing the new head gasket, it should go on dry or use some sort of gasket compound?
Take a look at the pics and let me know what you think.
Many thanks,
Eric
First thing, checked the compression to see if it was a viable candidate. Top cylinder 75, bottom 15. Sprayed more oil in the plug hole, now I have zippo for compression. Hmmm, not good.
May as well pull the head and see what I see. Expecting burned piston or badly scored cylinder. It all looks OK to me, but the head gasket looks very suspicious. As circled in the picture, there is a section that looks blown out to me. Also some blackness on the cylinder top surface and some darkness in the water jacket. Suspecting the head gasket is blown and was going last time it was running. Sitting for 10 more years didn't help it. Head bolts were fairly snug all the way out as if they had not been turned in 55 years, so guessing it may be original. Maybe not, but the gasket is OLD. It is making pressure in the crankcase when I turn it over as I get a little puff in the cylinder when I turn it over with the head off. Cylinder walls feel OK, the picture makes it look worse than what I can feel. Actually, the bottom cylinder looks a bit better to me than the top that had decent compression. Seems like the proper amount of play in the piston at the top, not too sloppy, not too tight. All in all seems to me like it should have compression with a new gasket. But, this is the first outboard motor I have ever taken apart, so I wanted to get a second or third opinion before I dump money into it. ($200 or so in parts for everything, well worth it if it's a runner, not so much if it needs more.)
One last question. When installing the new head gasket, it should go on dry or use some sort of gasket compound?
Take a look at the pics and let me know what you think.
Many thanks,
Eric