Rebuild blunder

fishndvm

Petty Officer 2nd Class
Joined
Jan 4, 2003
Messages
125
I recently acquired an old 1979 Johnson Seahorse 15hp. A local outboard mechanic was going to junk it, and I told him that I was looking for a clunker to break down to see how she ticks. I managed to take her completely apart, and put her back together again. She must have taken water into the crankcase, as it was rusted pretty good, but I managed to clean it up. I then put her back together again, but I have two questions. First, I realized that as I was putting tha two halves of the crankcase back together again, I could not spin the crank shaft if I snugged the bolts in. I assume that this is because I did not replace the gasket (remember...this is just for practice), and that that little bit of clearance made the difference. The second question is...when I finally got to replacing the plate that the magneto coil etc. mounts to, which sits around a circular collar formed by the two halves of the crankcase, it no longer fit! I don't get it. It seemed fool proof. The seam looked tight as a drum, but the darn plate wouldn't fit on it anymore. What went wrong?<br />If this had been a real job, I would have been in trouble. Could the fact that I may have left the crankcase bolts just a tad less than super tight to overcome the problem of the crankshaft not spinning have made the difference? As I said, the seam looked tight to me, but.......... Any advice would be appreciated.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Rebuild blunder

fishnfvm....what you probably didn't do was get the locator pins for crankshaft bearings into the holes in the bearings. And you don't want the crankcase halves bolts super tight. There is a specified torque value for the. Take SoLittles good advice and get the manual....it'll save ya' time, frustration and probably $$$$$$$.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Rebuild blunder

hello<br /> like the song lyrics say"Wrong. do it again."<br /> if your gonna practice try to practice right or you will develop a bad habit of if it works at all it works right. <br /> odds are the crank pins are not alined with the holes on the mains. I also have seen it when loquic primer was used that the gel seal kicked so quick it actually acted as a shim and caused the same stator no fit problem.<br /> if your going to practice act like its the real thing. that motors reciprocating assy is almost identical to all modern 2 stroke outboards from the 15 to the 250.
 

fishndvm

Petty Officer 2nd Class
Joined
Jan 4, 2003
Messages
125
Re: Rebuild blunder

Thanks for the replies. Rodbolt said that it could be that "the crank pins are not aligned with the holes on the mains." I'm not entirely sure what this means. The only "pin" that I recall is one on the housing (race?) of the center bearing. It came in two halves, and one half had a locator pin which fit into a depression in the crankcase. The two needle bearing assemblies then fit inside this collar, and the whole mess was essentially held together by a thin springlike wire clip that fit into a depression on one end of the collar. Is this what he is (you are) referring to?
 

dmurray

Seaman
Joined
Mar 13, 2004
Messages
51
Re: Rebuild blunder

Yes. It has a nipple that should rest firmly in the hole, which is dead center of the flange.
 
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