Crankshaft Seal

[metriccrescentwrench]

1990 Johnson 200.

I noticed some oil on and under the timer base. Not a lot, but definitely noticeable. SO... I'm guessing that means I'm going to be replacing the top crankshaft seal, doesn't it?

The diagram on shop2.evinrude.com shows a seal above the bearing assembly, as well as 2 o-rings below it, will I need to replace those o-rings as well?

Are there any tricks to replacing the seal I should know about? It looks straightforward, but ya' never can tell 'till you've actually done it.

 

[Big flop]

Re: Crankshaft Seal

It could be goo from stator
If it is oil clean it up as good as you can & keep
An eye on it.

 

[metriccrescentwrench]

Re: Crankshaft Seal

It's not "goo" from the stator, it's unburnt gas/oil. "Keep an eye on it" is not a viable option because I don't plan on pulling the flywheel after every couple hours of use. Maybe I should have added I noticed this because the flywheel is off while I'm replacing the timer base, I want to get this taken care of once and for all and be done with it.

 

[Big flop]

Re: Crankshaft Seal

You can remove top bearing retainer bolts & carefully pry the
End cap up to remove it. It will be very tight but it will come.
I have heard of people installing screw into seal housing &
Popping it out without removing end cap I've never tried it
That way. But sounds like you should replace it or you can
Get a lean top cylinder.

 

[daselbee]

Re: Crankshaft Seal

There are 8 bolts holding the crankcase head on to the top of the motor. Once you get those out, the most difficult part of the job remains. That crankcase head is really tight in there, and getting it lifted/pried up to get it out is a booger.

It is much easier to replace the seal with the crankcase head off. You run the risk of damaging the crank nose trying to get the seal out without removing the crankcase head.

I usually tap SIDEWAYS on one of the stator mounting posts, way down at the bottom, to provide a rotating effect to break it loose.
Light tapping until you can get a tool under the flange to begin lightly prying evenly to get it up and out.
I think I remember a place on the flange that is hanging over just a bit so that you can get a tool under to start the lifting process. It has to come out straight up, no cocking, or it will jam. It is in there about 1 inch deep.

Note I said lightly...you do not want to damage that mating flange surface.
Breaking it is gonna be a bad thing. It is very expensive (new), and even brings high dollar on EBay....

It may be possiible to rig a slide hammer to the stator mounting posts, and pull it out that way.

Once you have it out, pay special attention to the recirc line that runs from under there down to #6 crankcase cavity. There is a plastic check valve in that line. It provides oiling for the top main bearing, and is crucial to operation. Blow thru both ways to test. Arrow on the valve lets you know how the flow goes.

You can replace the upper main bearing in you want. It is available from ProMarineusa.com, but it is pricey too...about 100 bucks.
I press them out with a shop press. If not too stuck, a large vise and socket will press them out and in.

Putting it back is a breeze. Use the WOT timing bumper screw to get the rough position. It only goes one way, as the screw pattern is not symmetrical. Oil it up with TCW3 and tap it in evenly.

 

[Faztbullet]

Re: Crankshaft Seal

Just get ya a hook type seal remover or a self threading screw screwed into seal edge to remove. Grease seal lips, loctite edges and reinstall with a piece of PVC. The stator boss need not be removed unless you need to repair bearing. If bearing is replaced do not use a press,heat the housing witha torch oir oven. If you use a oven set it on top of a small saucepan and it wil drop out in pan when it gets hot enough. Have new bearing on hand and remove housing and just drop it in and as it cools the housing will tighten around it.

 

[metriccrescentwrench]

Re: Crankshaft Seal

Thanks everyone, lots of good information. If I had half a brain I'd have parted this engine out months ago and just took the loss of buying another one, but I guess I'm just stubborn.

If this seal is bad enough it's going to be just #1 cylinder that's running lean isn't it? And could that bad seal be making the engine idle really really bad?