1975 Evinrude 25hp top seal.

[redfisher2003]

I need to replace the top seal on this 25hp Evinrude (sn 25503). The service manual seiz not to just pull it out by any means but to get the proper tool. I asked my local Evinrude dealer about the tool and he does not have access to it. It looks like a standard seal I could tear up some and get it out, anybody have suggestions. A second question: has anybody done a electronic ignition up grade on this low tension flywheel magneto ignition system. I need to get rid of some excess play in the armature plate. When the plate is advanced the points gap changes because of excess clearance side to side. I have tried putting thin wraps of wire around the collar but it does not last too well. My plan is to try cleaning the inside diameter extensively and applying a coat of epoxy to remove the slop. Someone suggested a thin metal tape like product. Anyone have experence with armature plate slop?

 

[Joe Reeves]

Re: 1975 Evinrude 25hp top seal.

(Magneto Armature Plate)
(J. Reeves)

If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.

The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make an indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.

You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

Now, aout that seal..... Unless that seal is leaking and throwing the fuel/oil mixture within the armature plate/magneto area, leave it alone.

BUT, if you really need to replace it.... if the bearing is above the aluminum block casting, you can use a very thin screw driver to pry it out.

BUT AGAIN..... if the block casting is higher than the bearing, you'll need that special tool to remove it. Trying to pry it out in this scenario would cause damage to the block (breaking that block flange bearing), and you don't want that! Why a dealership would not have that tool is a mystery to me.

The alternative is to tear down the powerhead in order to remove the seal, and then to remove the seal. Hellava job!

http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

 

[F_R]

Re: 1975 Evinrude 25hp top seal.

Yep, the tool #377067 is listed as not available. The last price was $54 net anyway. At that price you could afford to pay somebody with the tool to pull the seal out.

Are you SURE the seal is leaking? I've seen many a motor all glopped up with black oily crud which was actually liquified grease from over-zealous lubricating of the armature plate mounting. It splatters all over everything and makes a mess. Oil that comes from the seal comes out clear and clean, just like it was when you put it in the tank. Yes, after it mixes with the above-mentioned grease it does add to the black mess.

I am kind of surprised that the armature plate is that loose. Earlier motors did have loosness problems after very high hours on the motor and they came out with an improved armature plate kit to correct it. But your 1975 should have the improved armature plate with the anodized bearing. And you are getting wire to fit in there yet? Doesn't sound right to me. Calls for further investigation.

 

[mikesea]

Re: 1975 Evinrude 25hp top seal.

I remember working for a guy about 20 yrs ago.I did some of his small outboards.There was some kind of problem with an engine with points,and he gave me a kit that is used in lawnmowers and other small engines,it was a unit that replaced the points and supposedly was an improvement.I think it worked off the magnets in the flywheel,you needed one for each cyl.My brain farts wont let me remember much more but maybe someone can help you and me out with the device .Meanwhile I'll search the net

 

[steelespike]

Re: 1975 Evinrude 25hp top seal.

There should be a Magna tune kit right here at iboats.
18-5101.Not for engines with charging systems.
I wouldn't change the system.Parts for these systems are readily available.And you couldn't tell the difference between properly tuned magneto and the magnatune.

 

[redfisher2003]

Re: 1975 Evinrude 25hp top seal.

Captain Joe, FR, , mikesea, and steelespike,
You know I did try the hammer screwdriver method about 2 years ago. And I just could not take up enough slack so I turned to the very fine copper wires which did work for two years. The dealer convinced me at the time I was playing with the slack that the seal was probably not leaking and I guess I am still not sure. Perhaps this latest grease/oil muck problem was me lubricating the the plate. The wire fix finally needed to be redone maybe I messed it up with the librication I used at the time.

I am still thinking about changing out the points for electronic ignition (there is no charging system on this motor) because of the play in the armature plate. I had a big old green machine weed eater you could not get points for and I just wired in this little rectangluar piece of metal and wires and the thing jumped back to life. I bypassed the points it seems so I am thinking I could bypass the points on this motor and then the gap problem would get solved. The motor does have good compression though it will not idle as slow as I would like for trolling, it is great for pushing my little home built clamming skiff in the Texas gulf bays. I do use a much newer and cleaner motor in our lakes where I troll for striper and other fish. I have yet to let the dealer look at the motor maybe it is time, at least the seal could be changed if it is needed. Steelspike am I thinking right with that Magna tune replacing the points and therefore solving my armature palet slop issure?

That kit worked like a charm on the weedeater.

 

[G DANE]

Re: 1975 Evinrude 25hp top seal.

If you use the Joe Reeves method and a piece of thin brass coil band for fitting bearings in worn bores ( available at machine shops ) it will last. If upper seal leaks, it will be spitting oil all over motor, continiously. On motors prevoius to 1975, the seal is easily replaceable, just leave the steel shell in place. I did one where there was place enough to put a standard new type shaft seal on top of the old one, sealed it better as there was a small grove in cranckshaft where the oroginal seal rode.

 

[Joe Reeves]

Re: 1975 Evinrude 25hp top seal.

Red..... If you couldn't take up the slack in that armature plate wobble, you've probably got the aluminum ring on upside down. It should be installed so that the wide flat portion of it faces upwards against the brass retaining ring.

I state the above due to the fact that if you tap that brass ring just slightly too much, bending it down a few thousands of a inch, the armature plate will lock up.

 

[redfisher2003]

Re: 1975 Evinrude 25hp top seal.

G Dane, and Cap Joe,
I am going to play with the motor this weekend. I noticed when looking back at my first effort in 2004 both of you helped me when I bought the motor. Thanks again guys. I do want to try to check that seal maybe the dealer can put one in for a decent price. It does more or less have a thin film of oil on everything under the flywheel. As to the armature plate wobble, answer this one question: If I get that magnatune ignition kit to by pass the points will the armature plate play still be a factor? To my way of thinking the contact points are not used at all so therefore the armature plate wobble would have an effect on the motor performance. Even the thin film of oil should not be a factor.

Redfisher

 

[byacey]

Re: 1975 Evinrude 25hp top seal.

I replaced the seal on my 40 HP, and what a difference it made for idling. I can troll with the motor now, and it runs dead slow very reliably. Before it would choke hack and die after 30 seconds or so. If you can't remove the play from the armature plate, some brass shim stock of the appropriate thickness might work well for you. I peened the brass ring on mine and had no problems tightening it up enough. In fact I over did it the first time and had to flatten it out again. Go easy and repeat the procedure a few times until you get it right.

 

[byacey]

Re: 1975 Evinrude 25hp top seal.

Oh, and don't ask how I replaced the seal. It wasn't fun, and I wouldn't recommend what I did to anyone. I was lucky not to get metal bits into the upper bearing. Find someone with the proper tool.

 

[redfisher2003]

Re: 1975 Evinrude 25hp top seal.

Guys if you see this post I changed out the points with electronic modules this Christmas and the motor is by far a better sounding engine. It did not look like the seal actually needed changing when I got in there to do the job so I just did the conversion by removing the movable side of the points. Then splicing in the modules to the cut off switch wire for each cylinder. It idles and starts like new. The armature wobble does not seem to effect the airgap with the primary coil and flywheel. I will report if I have problems but as of today I am thrilled with the difference electronic ignition makes.

 

[emdsapmgr]

Re: 1975 Evinrude 25hp top seal.

I had the same seal go on my 79 35hp. turned out the upper bearing was shot and the crank "wobbled" enough to destroy the seal. Had to take it down to replace the bearing. Any chance your crank is "loose" in the upper bearing?