Missing Gasket question

[Coosa River]

I have a 1971 25hp Evinrude (25103S). I was getting bypass oil up on the points, so I replaced that top seal. It held for a while, but now is leaking by again. I'm thinking that there is possible bearing problems, or the O ring with the top bearing is shot. It appears that the crankshaft is tight enough....and the motor will run, but doesn't idle down very well.....will die after a few seconds back at idle speed.
Anyway, I'm thinking about breaking the crank case in half and taking a look.....possibly replacing the bearings / seals / O rings. I'm looking on this parts list/view.....and I'm not seeing a gasket where the two halves of the block comes together. Is there not one, and do you use some type of other sealer if there ain't.

Parts View ... http://www.lmmarine.net/pages/parts/viewbybrand/74/1424/30342/709/default.aspx

Thanks for the advice.....and possible comments about my reoccurring oil leak from that top seal

Coosa River

 

[F_R]

Re: Missing Gasket question

I have a 1971 25hp Evinrude (25103S). I was getting bypass oil up on the points, so I replaced that top seal. It held for a while, but now is leaking by again. I'm thinking that there is possible bearing problems, or the O ring with the top bearing is shot. It appears that the crankshaft is tight enough....and the motor will run, but doesn't idle down very well.....will die after a few seconds back at idle speed.
Anyway, I'm thinking about breaking the crank case in half and taking a look.....possibly replacing the bearings / seals / O rings. I'm looking on this parts list/view.....and I'm not seeing a gasket where the two halves of the block comes together. Is there not one, and do you use some type of other sealer if there ain't.

Parts View ... http://www.lmmarine.net/pages/parts/viewbybrand/74/1424/30342/709/default.aspx

Thanks for the advice.....and possible comments about my reoccurring oil leak from that top seal

Coosa River

Are you positive it is a leaking seal? If the armature plate mounting is over-lubricated, vibration liquifies the grease and splatters it all over the place. Oil coming from the seal looks like the stuff you put in the gas tank--because that's what it is.

 

[Coosa River]

Re: Missing Gasket question

I'm sure it's coming from the inside of the motor....through the top oil seal. It's oily, sticky stuff.
One thing that I noticed....when I pulled the old seal off, and I think it was original factory.....it was a much heavier seal than this after market one that I ordered. The old one was much thicker, and had a double wiper type seal. This new one was only single wiper.
Another thing that I notice is.....I have the flywheel off now.....turning the crankshaft with a wrench, I can hear air either sucking in or blowing out around the new seal that I had installed.....I think it is blowing out, and is the reason for the oil all under/around the armature plate.

Let me ask this also....does that top bearing have it's own seal ? liked a normal sealed bearing would ?

I may pop this new seal back out tomorrow, and inspect what I can from the top again.....of course, then I'll need to order another seal too. I would really like to get this problem solved if I decide to go into it again.

Coosa River

 

[14ftgrumman]

Re: Missing Gasket question

No gasket between the crank case halves, it's a machine fit. Any gsket or sealer or silicone will not let the crankcase seal the way it should. Re-torque the bolts in the proper sequence and to the proper torque value in steps, don't torque it to spec in one step.

 

[Coosa River]

Re: Missing Gasket question

Well that answers the question about the gasket.....now to figure out which direction to take to get the oil stopped from blowing out of that top. I've never broke an outboard completely in half before, so this would be new territory for me. I do have all the proper tools to do it with though.

Question.....is that top seal supposed to be able to hold in engine/block pressure ? I just have a hard time trying to figure out how that little ole thin oil seal on its own, is gonna hold much back to start with. I've got to be missing something here.

Coosa River

 

[Dhadley]

Re: Missing Gasket question

Gel Seal is used between the halves, no gasket.

There is a seal in the top of the bearing. Are you sure the oil is coming from the seal area? Or is it coming up past the bearing itself?

 

[Coosa River]

Re: Missing Gasket question

Hmmmm......I'm not sure if it is leaking around the bearing or through the bearing. All I have done so far is pull the oil seal off that sets on top of that bearing.....and tapped in a new one. I really didn't look hard down on that bearing......but I don't remember seeing anything that looking to be a factory sealed bearing. I'm thinking that way too much oil is being able to pass through this bearing section, and that it is more than what this thin oil seal can hold back on its own.

I appreciate you fellers hanging around on here.....I'll probably have to get back on here after I tear this thing in half.

Oh yes....need a clarification on the gel seal between the halves. Twas posted earlier that nothing goes in between.....not trying to start a disagreement, but I'm thrown off a little bit now on what to do when I put this thing back together.

Coosa River

 

[bktheking]

Re: Missing Gasket question

OMC sells it, comes in what lookes like a locktite tube part #0324073, it's red and looks like jelly and I used it on my 9.9 when I assembled the two halves as recommended by my dealer and the manual.

 

[Coosa River]

Re: Missing Gasket question

Got it....will check on some when I order new seal and possible bearings. I suspect that this gel is applied thin and evenly ain't it. ???

Coosa River

 

[bktheking]

Re: Missing Gasket question

Got it....will check on some when I order new seal and possible bearings. I suspect that this gel is applied thin and evenly ain't it. ???

Coosa River

Yes and you don't need a very wide bead either, excess will come out between the halves.

 

[F_R]

Re: Missing Gasket question

Well that answers the question about the gasket.....now to figure out which direction to take to get the oil stopped from blowing out of that top. I've never broke an outboard completely in half before, so this would be new territory for me. I do have all the proper tools to do it with though.

Question.....is that top seal supposed to be able to hold in engine/block pressure ? I just have a hard time trying to figure out how that little ole thin oil seal on its own, is gonna hold much back to start with. I've got to be missing something here.

Coosa River

OK, so the sucking and blowing sound confirms the seal is leaking. There is no need to tear it down to replace it--as you said, you have already done it once. Yes, a new bearing comes with a seal in it---the seal that you replaced. Just do it again with the right seal.

I suggest you get a new, correct, OEM seal from a dealer. It is part number 305987. Of course it is supposed to withstand the pressures inside which are only on the order of about 5 psi.

 

[Coosa River]

Re: Missing Gasket question

Just replacing that top seal would be a whole lot simpler job. For what a new seal cost, I think I'll just try another one and see if it will hold before busting this thing up. Now that it's getting nasty and cold, I have time to fiddle with this thing....just want to get it right before these crappie start up in late Feb on Logan Martin lake.

Thanks Fellers,

Coosa River

 

[Coosa River]

Re: Missing Gasket question

FR / anyone else
I have another question about the seal.

Looking in the parts department here on IB.......the replacement seal that they show, looks much like the one that was sent to me by another dealer. As I mentioned earlier, the old seal that I took out looks factory to me....and is much heavier built than these factory replacements that I'm looking at. These that I've looked at so far only have a single wing that would point angling downward toward the crank. The old seal that I took out is winged in both directions.....and I would assume that it is made to prevent both blowing out of the case or sucking into the case.
Now, I think that I'm mostly having a problem with blowing outward, so this single sided (angling downward) seal should help prevent that......but this old seal was built to seal both directions for a purpose.
The only replacements that I find are made by either Mallory or Sierra........I'm not sure there is much difference in the two.... just looking at the pics of them.

What do you think....looking for advice here......and looking for the absolute factory type seal if it is still being made. This is a 1971 25hp Evinrude ...model # 25103S


Thanks again fellers......I'm gaining from your knowledge and experience.

Coosa River

 

[F_R]

Re: Missing Gasket question

FR / anyone else
I have another question about the seal.

Looking in the parts department here on IB.......the replacement seal that they show, looks much like the one that was sent to me by another dealer. As I mentioned earlier, the old seal that I took out looks factory to me....and is much heavier built than these factory replacements that I'm looking at. These that I've looked at so far only have a single wing that would point angling downward toward the crank. The old seal that I took out is winged in both directions.....and I would assume that it is made to prevent both blowing out of the case or sucking into the case.
Now, I think that I'm mostly having a problem with blowing outward, so this single sided (angling downward) seal should help prevent that......but this old seal was built to seal both directions for a purpose.
The only replacements that I find are made by either Mallory or Sierra........I'm not sure there is much difference in the two.... just looking at the pics of them.

What do you think....looking for advice here......and looking for the absolute factory type seal if it is still being made. This is a 1971 25hp Evinrude ...model # 25103S


Thanks again fellers......I'm gaining from your knowledge and experience.

Coosa River

OK, here is what I know:
305987 is still a good number. I don't know why they are sending you something else unless the original design is no longer made and they are substituting from another Mfr. But they usually change the part number when they do that.

I you go back a few years, you will see that they did indeed use a single lip seal and it worked perfectly well. That single lip had a "garter" spring around it. Did the one they sent you have the spring? The old single lip seal was part number 303804. What was the part number of the one they sent you?

The second lip was primarilly to keep dirt from falling down into the seal. Although it may have some secondary benefit such as you suggest. The upper lip was not gartered.

So, if the seal they are sending fits, and has the garter spring it should work. However, I believe I would still see if I could find a "real" 305987. Go to www.sea-way.com for the phone number and give them a call.

And just a bit more of a note: If the bearing is loose (crankshaft moving back and forth), no seal is going to hold.

 

[F_R]

Re: Missing Gasket question

OK, here is what I know:
305987 is still a good number. I don't know why they are sending you something else unless the original design is no longer made and they are substituting from another Mfr. But they usually change the part number when they do that.

I you go back a few years, you will see that they did indeed use a single lip seal and it worked perfectly well. That single lip had a "garter" spring around it. Did the one they sent you have the spring? The old single lip seal was part number 303804. What was the part number of the one they sent you?

The second lip was primarilly to keep dirt from falling down into the seal. Although it may have some secondary benefit such as you suggest. The upper lip was not gartered.

So, if the seal they are sending fits, and has the garter spring it should work. However, I believe I would still see if I could find a "real" 305987. Go to www.sea-way.com for the phone number and give them a call.

And just a bit more of a note: If the bearing is loose (crankshaft moving back and forth), no seal is going to hold.

Follow-up:

Just noticed you mentioned the seal from iboats. The iboats seal would be supplied by Sierra Marine. That also may be what you received. And it would explain why it is different than the OEM 305987. Again, I suggest that you try to get an OEM seal.

 

[Coosa River]

Re: Missing Gasket question

FR

I walked back out to the shop.....looking around on the work bench....and I hadn't thrown the package away on the seal I ordered, nor had I thrown away my old seal either.

I had ordered this from L&M down here in the south end of my state. The package is Evinrude/Johnson .... Bombardier.... Powerhead seal p/n 305987.

I was hoping to find some # 's on my old seal, but I can't find any maker marks on it. It does have the spring that you mentioned on it. I seriously didn't look that close at the new one that I bought....other than I noticed it was single wipered.

I'm getting the feeling that the engineers have changed from their original design, and this single wiper is what I'm gonna have to settle for. If that's what they've done, then I would say that they made a drastic change.......my old seal had about a 1/4 inch width of rubber touching the shaft all the way around (wiper both directions). This new one would be lucky to touch 1/32 of an inch (wiper in one direction).
My crank was clean and smooth before I installed the last one, so I'm pretty sure that the crank didn't chew it up. Now...the bearings condition. As old as this motor is, I'm sure there is some wear....and probably could not see it without breaking the case down. I have grabbed hold on the crank to see if I could make it wobble any....no sign of that at all.
This is a pretty fair old/tight motor if I can get the oil stopped from blowing up under the flywheel. I thought maybe there was a case leak on either side of the seal, but that doesn't seem to be the case here. I'm 99% sure that the grey color oily stuff is blowing out from the seal where it meets the shaft. It appears that the oil travels up the shaft to the bottom side of the cam....then starts slinging out on the other parts/points from that area.

Another new seal only cost about $10.....I think I'll just install one more, and go from there. I would like to depend on skill rather than luck, but maybe I need a little luck this next time around.

Still got my ears open for more advice/suggestions,

Coosa River

 

[F_R]

Re: Missing Gasket question

The "gray colored" stuff confuses me. Add that to the sucking and blowing you hear and I really get confused.

As I said way back, the oil in the bearing should be just as clean as the fuel in your tank, because that is what it is. The crankcase in a two-stroke is constantly being washed down by the fuel charge passing through it. They don't get nasty dirty inside like a four-stroke (listen up, you four stroke fans).

Of course if it is being contaminated AFTER it leaks out, it will take on the color of the contaminant. That is why I suggested the armature plate lubricating grease.

Now, trying to make sense of this situation, I'm wondering what could make the oil gray. Nothing I can think of other than possible water intrusion into the crankcase, causing an oil-water emulsion. Mind you, that is a goofy wild guess. If water is getting into the crankcase, the projected life span of the whole powerhead is very short.

And then there is the air sound. My head hurts.

 

[Coosa River]

Re: Missing Gasket question

Ha Ha Ha !!! Sorry I'm bending your brain .....but you're actually helping me by making me study this thing harder. I think I'll take a small smear of soap and place around the seal.....then turn the crank.....bubbles up should tell me if it's air blowing out. I guess if it sucks it in, then I'll have a smear of soap in my motor. I'm not sure if knowing that will help me solve the problem though.

The grayish colored look to the oil makes me think mixing with water also. It's not thick as grease, but not thin as oil either. I think I'll go back out there and see if I can get this new seal back out. I know that I'll ruin it, but I want to see what color the oil is under that seal now (and top of that bearing).

I assume that if the oil under there is clean looking, then I can rule out water inside the case......and assume that the grayish tint is coming from getting dirty after it leaves the crankcase.

OK.....I'm off to see what I can tear up now.....will check back in here later to see if there are any more suggestions.

Thanks again,

Coosa River

 

[Coosa River]

Re: Missing Gasket question

Well....that didn't take long as I thought. The oily stuff under the seal looked like oil. So....as humid and cool as it has been here lately, maybe condensation is just getting under the flywheel while this thing is setting cold...causing that oil/water look.

Sorry I have left my original question about the gasket, but now I have to ask about the bearing that I'm looking down on. I can plainly see all the tops of the rollers on this bearing. 1, Is that normal at this point ? 2, Should there be any odd gaps between any of the rollers ? There is about a 1/4 inch empty space bare in one place (no rollers)....maybe that much again in another spot. If I didn't know better, I would look at this and say there were some rollers missing. All are upright, none laying over, and no metal grindings seen. If some are missing, where in the heck did they go. Please tell me that what I'm looking down on is "normal". I turned the crank and watch the rollers turn....what's in there seem to turn smoothly.....but it dang sure looks like some missing to me. In the past when I look at most roller bearings, they usually look like they are stack in there side by side like cord wood....no gaps.

Coosa River

 

[14ftgrumman]

Re: Missing Gasket question

I've noticed some of the same gook as you describe, but not to eexcess in either of my 72's (20HP and 25HP). Hinda like grey slime. I beleive it's lube from the brass bushing on the mag plate. Had it on my '59 18HP Fast Twin.

A little that got onto your finger made a smear that got all over your hand and took some real good hand cleaner to get it off.

On the block gasket, I've used a gasket cinch when I went through a Suzuki motorcycle (4 stroke). Was white, never used anything on the OMC outboards, and so far, haven't had a problem. Just made sure both halves were clean and dry. I felt that there was none from the factory, so there must not be any sealer or gasket needed. But then again, all I've got is a Sealoc manual, and my own pea brain and strange way of seeing things. (just ask my wife)