1979 80hp mercury

[cm_wangs]

Could anyone offer an option on how to replace the prop shaft seal. I don't have the tool to get the ____ off (don't know what it is called) and any ideas on what the seal might cost?




FYI about the engine:

It had a lower compression in one of the cylinders. Before and after each use (once a week) I am using deep creep in the spark plug holes. This engine continues to improve. To keep it running a couple of years ago I added the smallest fuel pump I could and adjusted the ideal speed. This engine has gained compression in the bad cylinder!!! but not completely back. Just an FYI in case someone is thinking about parting out an older engine. This seems to be working, the more I use it the better its been.

 

[emckelvy]

Re: 1979 80hp mercury

Unless you remove the propshaft bearing carrier and drive the seals out, about the only way to remove them in place is to use some sort of puller screw to grab hold of the old seal, then yank it out.

I've seen a special tool for pulling Johnrude crankshaft seals, which was basically a very thinwall pipe which would fit over the shaft, and had external threads that would grip the old seal, to be able to pull it out. But don't know if anything like that is available for Merc propshafts.

I've found that a drywall screw is small enough, sharp enough, and has sufficiently agressive threads to 'bite' into the seal and be able to pry it out. Then you just drive the new seals in with a suitably-sized piece of pipe. Be careful not to scratch the propshaft surface while you're pulling the old seals out.

Be sure you orient the new seals such that the inner one (facing the oil-side of the gearcase) has the lips of the seal pointing inwards (i.e., away from you as you drive it in); the outer seal should have its lips pointing towards you as you install it.

And it sounds like your low compression issue may be due to carbon-stuck rings, Seafoam is pretty effective in curing this type of problem. Note that in addition to the Deep Creep spray treatments, you can add a dose of Seafoam to your fuel to get even more cleaning effect.

Look up parts for your motor here:

http://www.dougrussell.com/partscatalog/collections/index.cfm?fuseaction=collectdetails&colid=01

HTH & G'luck......ed