1973 25 hp gear head assy. question

[jr43]

in the gear head is it possible to change out the propeller shaft seal if so what seal # do you use or do you have to change out the assy.

 

[Boobie]

The parts book shows it as an assy due to the way it's designed.

 

[racerone]

You pop out the washer at the back and change the seal out.-----You measure the seal and get a replacement ???

 

[fdrgator]

Yes, they have that stainless steel fish line keeper-outer pressed in aft of the seal. A lot of them have fallen out, but if it is still there, remove it and change the seal as always. I believe it is the same seal as previous ones without the keeper-outer.

 

[Boobie]

I can remember some head assy's where you couldn't pop that washer out.

 

[Boobie]

The seal was part of the gear head casting.

 

[jr43]

thanks again for all the help found the right seal to day replaced it machined a news stainless steel end cap assembled and preassure tested all good there, now for the next issue if found after running today. I removed the old plugs to install new ones the top cyl. spark plug still looks new very small amount of carbon build up on the tip and there is a little bit of water around the threads. bottom cyl is light brown as it should be. compression test shows 94 top 97 bottom idles with out missing a little stumble then runs up to 5200 rpm wot. I am thinking head gasket ? any suggestions or advise thanks in advance.

 

[fdrgator]

You must not ignore that water issue. If it is coming from inside the cylinder, yes it could be the head gasket, or the exhaust cover gasket. And if it is getting water inside the cylinder, it can/will make it misfire. It will also destroy the motor.

If it is coming from outside the cylinder (thermostat), it may cause the spar plug to arc out and misfire. At least that is not so destructive.

 

[jr43]

the water is for sure inside cly ran a 15 min. shut it off and pllued the spark plug it had a small amount of water between the insulator and electrode of plug Im going to pick up exhast housing gasket and new head gasket and replace . a cracked head easy to identify ?

 

[jr43]

ok thanks.Ill just go ahead and replace inner cover while im in there that will eliminate the possibility of that. If there is glazing or scoring that would require a coplete overhaul of power head what would one expect to pay for that? never been that far into a engine project like that

 

[jr43]

ok thankyo for all of your advise