Crankcase Gasket Replacement

[JDusza]

I am rebuilding a 15 hp. When I replace the gaskets, should I also use a gasket sealer as an insurance policy?
Thank you.

 

[bktheking]

Re: Crankcase Gasket Replacement

What yr 15? Most gaskets yes, head gasket no, the crankcase halves use an omc gel sealant.

 

[JDusza]

Re: Crankcase Gasket Replacement

Simple question ; what year is the 15 hp?
Answer, not so.
I broke a crankshaft in a 1979 and mucked up a threaded boss on the case when tearing down.
I have a 1987 Johnson case, pistons, and crank. The rest, I'll pull off the 1979.
Thank you.

 

[bktheking]

Re: Crankcase Gasket Replacement

Be aware there was a lower seal change if memory serves , there were 2 in the later models and 1 in the early models depending on what parts you are interchanging. You will want to use the crackcase head off of a newer motor to match the powerhead you are putting on.

 

[JDusza]

Re: Crankcase Gasket Replacement

Yes. Thank you. I'm on it.
To my untrained brain, it looks like a "belt and suspenders" kind of thing on the '87. As you probalby know, the crank, case, bearings are all the same. And, the vertical position of the crank in the case MUST be the same. It appears to me that a second seal was added to the '87 (and nothing else). I do have both crankcase heads, so, if the '87 is deeper to accept two seals, OK. If I stick with one seal, I'll use the '79 head.
I think I'm OK.
TY

 

[bktheking]

Re: Crankcase Gasket Replacement

Know all about them, i swapped my 83 out for an 88 on my 9.9, had to do my homework when I did the swap, wanted to pass along the info.

 

[JDusza]

Re: Crankcase Gasket Replacement

Thanks for the heads up.
Right now it looks like a Harley; parts in a basket.
I'll start the rebuild this weekend.
Woo hoo!