1955 evinrude 25hp bigtwin L/U leaking and a couple of other things

[Idaho]

I posted this a few days ago but in the wrong forum. So lets try this again...

I have a few questions here so advice regarding any question is welcome.

I Recently Bought A Boat With An 25 Hp Evinrude Aquasonic Bigtwin On It. The Numbers Found On It Were 25920 And 18571.

When I Drained The Lower Unit Oil Water Came Out First Followed By A Small Amount Of Oil... so it is obviously leaking. I Took The Screws Out Of The Skeg And Began To Remove It But When I Saw The Gears On The Inside It Looked Like The Type Of Thing That Would Come Apart Easily And Never Go Back Together Again. I ordered a L/U seal kit and an impellor (which probably needs replaced) from mastertech marine. It will be here next week...

So My Queston Is... Can I Fix The Leak And Replace The Seals Without Taking the Skeg completely off And Exposing The Gears, And If I Do Take Apart The Lower Unit Will The Gears Fall Apart In My Hand And Be Really Hard To Get Back Together Again? I don't have a manual so I am reluctant to take something apart which will be hard to put back together without instructions.

Also, I have started the motor and know that it runs but it would die after a few minutes. I took the carb apart and it appears clean, the float is in decent shape but I noticed that the cork gaskets which seal the two adjustment knobs were broken and they fell apart when I removed the knobs.... I figured that it would be cheaper and easier to put teflon tape on the thread and screw them back in place than to buy a whole carb rebuild kit.
Do you think that this will work and is it possible that those seals being broken would cause the motor to die.

One last thing. Around the spark arrester in the air intake chamber was what looked like fiberglass insulation. I pulled it off. I am assuming that someone put this in there to act as an air filter. I have been told that outboards often don't have air filters.... Does this sound correct or was this a real air filter that I should replace.


Thanks

 

[R.Johnson]

Re: 1955 evinrude 25hp bigtwin L/U leaking and a couple of other things

On an engine that age, you would want to replace the drive shaft seal, prop shaft seal, shift rod o-ring, and gasket, seal carrier o-ring, string seal around the skeg. You may well need the entire water pump assembly. The gearcase is quite easy, just lay the parts' out in order on a clean work cloth, or sheet. You can't tape the needle valves, you need the proper packing. This can get exspensive before you are all done. If you want an engine you can count on, thats what it takes.

 

[F_R]

Re: 1955 evinrude 25hp bigtwin L/U leaking and a couple of other things

Tell ya what, it would be much more difficult to replace the seals the way you are thinking than to go ahead and take it apart and do it right. You are also kidding yourself if you think the drive shaft seal and shift rod seals don't also need replacement.

I'll guarantee that motor has bad ignition coils unless they have already been replaced. That's why it won't run

I've tried the Teflon tape thing and it doesn't work. Get a carburetor repair kit and do it right.

That is a silencer on the front of the carburetor. It came from the factory with the fiberglass material in it to muffle the noise. A lot of people take it out. In fact, I hear there was a factory service bulletin saying to remove it.

You are trying to fix up this motor with no experience and spending no money. It isn't going to happen. Be prepared to spend a couple hundred $ or leave it alone and don't mess it up for the next guy. Part of that $ is for a good manual...your best investment.

 

[Idaho]

Re: 1955 evinrude 25hp bigtwin L/U leaking and a couple of other things

Thanks for all the advice. I'll be getting a manual shortly and have a lower unit seal kit coming in the mail so that will be the first project.

 

[Idaho]

Re: 1955 evinrude 25hp bigtwin L/U leaking and a couple of other things

I rebuilt the lower unit and replaced all the seals. As I put all the gears and moving parts back together I spread a thin film of grease over them. I took photos as I disassembled it so I know that I put it back in the correct order. I did all that with out the book. I finally did get a copy of the book and read through the procedure. It seems that I did everything correctly except that I put gasket sealer on while reassembling it. Have any idea if this was a bad idea?

Anyway I haven't put the lower unit back on the engine yet because I need a few parts before I get the motor running well. The only thing that concerns me is that the drive shaft is pretty hard to turn by hand. It turns alright, the gear shifter works, and it turns the prop but it takes a little muscle to turn it. I traced the stiffness to the lower bearing on the driveshaft (the one that is above the gear on the driveshaft. I don't remember turning the driveshaft before beginning the project so I don't have anything to compare it to. Also I haven't put gear oil in it yet in case I need to take it apart again...that could be part of the problem.

Next I am ordering new coils, condensers and points and probably a head gasket.

Any advice is welcome

Thanks Eddie