1981 Evinrude 25hp Project Motor

[vinmega]

Hi Everyone,
I have posted here before about my 1981 evinrude 25hp having a powerhead gasket leak. I temporarily sealed that leak with some quick steel. The motor does not run with the cover on, it dies.
I also noticed this tube coming from the bottom of the carb and goes into somewhere behind and above the carb.
See pics.
The first pic is to show the position, you are looking at the port side of the motor, carb is to the right flywheel above left.
The second pic is the tube, it looks like it popped out of something because the clamp is still on it. you can see the carb behind it in this pic, but it looks like it went into something above/behind the carb.

2 questions:
1) Since the motor does not seem to run with the cover on, should I just pull the powerhead and replace the gasket?
2) What is this tube that leaks 2 stroke oil out and what does it go into?
This motor has been a challenge, but I am not giving up.
Motor runs fine with cover off, but runs 'bumpy' at idle.
Any advice?
Pics attached.

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

I think that tube may go to the intake manifold. Should be a nipple for it.
Take a look at my video. See the white tube at about 11-14 seconds.
Hope this helps.

http://www.youtube.com/watch?v=gfBQ0_lBkfU

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

Here is what mine looks like off.
Thanks for the assist.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

OK, so i got the powerhead off, and replaced the powerhead gasket and reattached the powerhead. But I broke this trying to get the r/n/f spring plunger gear cam shift thing. I broke it in two.
How do I get this this thing back in place, and can I crazy glue it? I am 100% stumped by this part. I put the powerhead back on and connected most everything else. Cant test the motor because I broke that, and I broke a piece of the fuel pump. Big hands dont work well with these motors, but I feel pretty proud that I got it done. I cant wait until new fuel filter comes in and I can test it out.
See pics, Any advice on how best to repair that plunger/spring thing?
If it was not for this board, I would never have gotten into fixing my motors. As far as the 2 bolts that are in the pan, somebody had a tip about heating and bending the wrench! Now I have my own specialty tool! What a great idea thanks!
Pic 1 is plunger thing
Pic 2 is after gasket was replaced
Pic 3 is before gasket was replaced.

 

[nphilbro]

Re: 1981 Evinrude 25hp Project Motor

Any chance you can open this in MS Paint and put an arrow to the piece you're talking about? I can't tell from these photos. Or if you didn't already, a picture of the broken part and the break itself.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

See here.
Do you all have any tips on how to get this thing back together? Cant seem to fenagle this plunger piece into place.

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

See here.
Do you all have any tips on how to get this thing back together? Cant seem to fenagle this plunger piece into place.

If you snapped it, I'm not sure how well crazy glue will hold. Wouldn't hurt to try. Also, JB weld has been known to perform some miracles. Also, that part (#75) is not terribly expensive, about $11...

http://www.marineengine.com/parts/j...turer=Evinrude&section=Cylinder+And+Crankcase

Also, you can try the salvage yards listed in the Top Secret Files.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

OK, but how do I position it in place so that I get that little metal link on the bottom and spring to fit?

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

OK, but how do I position it in place so that I get that little metal link on the bottom and spring to fit?

I know a guy that's doing a rebuild on a similar motor, maybe he can help?...
http://forums.iboats.com/showthread.php?t=561653
http://www.tinboats.net/forum/viewtopic.php?f=4&t=26650

 

[2manband]

Re: 1981 Evinrude 25hp Project Motor

I've fixed cylindrical plastic parts before by doing this:

Square up the ends of the break - take off just enough to square them.

Find the center of the circle on each end, and center punch it.

Drill a hole where you center punched. Be very careful to drill straight, and use a drill press if you have one.

Find a screw or bolt that's the right size and threads all the way to the top. Put a few drops of glue or epoxy into one of the holes you drilled and thread the screw in about half way. (You should have drilled the holes to a depth of just a little more than half the length of the screw)

Cut off the screw head and file the stub to a point.

Put a few drops of glue or epoxy into the hole on the other side, and then thread that onto the other end of the screw (backwards thread this time)

Run the two parts together until you've matched the original length. You'll be left with a gap in the middle from where you removed material to square up the joint. Use some 5 minute epoxy putty to fill the gap, smoosh it in there with your fingers and smooth it to the contours of the other part.

Lots of times that does the trick and the steel reinforced break area is every bit as strong as the rest of the part.

Having said that though - if you can get a new one for $11, I would probably go that route. I've only ever performed this kind of repair if a replacement isn't available, or if it's too expensive.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

You guys are very helpful, thank you. Now i have a new problem! I got it started and running, but now no water comes through! I took off the hose from the powerhead to where it goes out the peehole, it was fine and not clogged. The 2 exhaust holes have air coming out, but no water. The pee hole had steam coming out. It was hot so i shut it down.
When i took the powerhead off i remember there was a copper water pipe on the manifold. Keep in mind the motor was peeing fine before i changed the gasket.
Any thoughts? When i lowered the powerhead back on to the lower, was i supposed to put that copper water pipe in a specific place?

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

You guys are very helpful, thank you. Now i have a new problem! I got it started and running, but now no water comes through! I took off the hose from the powerhead to where it goes out the peehole, it was fine and not clogged. The 2 exhaust holes have air coming out, but no water. The pee hole had steam coming out. It was hot so i shut it down.
When i took the powerhead off i remember there was a copper water pipe on the manifold. Keep in mind the motor was peeing fine before i changed the gasket.
Any thoughts? When i lowered the powerhead back on to the lower, was i supposed to put that copper water pipe in a specific place?

You will have to drop the LU to align the water tube into the water pump.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

Thank you!
So dropping the lower is easier than removing the powerhead? I am almost there!!! I was so excited when it ran real smooth with the new gasket and then when I saw it getting hot and no water pumping I shut it down.
Any tips on how to get the lower unit off on this motor? Once I get it off, what am I looking for to place the water tube into?
Much appreciated.

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

Thank you!
So dropping the lower is easier than removing the powerhead? I am almost there!!! I was so excited when it ran real smooth with the new gasket and then when I saw it getting hot and no water pumping I shut it down.
Any tips on how to get the lower unit off on this motor? Once I get it off, what am I looking for to place the water tube into?
Much appreciated.

Manual sent. Also, replacing the water pump is real good insurance.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

Advice taken, I am going to get a new water pump kit tomorrow when I take the LU off.
Thanks again!

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

Motor is a success!
Thank you all for your help. Especially Jasper.

check it out!
http://www.youtube.com/watch?v=hg5Tc2sF-Bs&feature=plcp

 

[jasper60103]

Re: 1981 Evinrude 25hp Project Motor

Glad to hear you got her going. Better get a bigger bucket.
Thanks for the update.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

So I took her out for a test run on the river today, runs like a champ at full idle, then when warmed up, if I let off throttle it dies in low speed. Then its a big hassle to start it back up. Got it running again, but it was very 'boggy'. Died if I tried to open it up too much...is this a carb issue? I saw fuel leaking from the bottom of the carb, so I headed back to the dock and called it a day...what gives?
I also want to mention that the low speed, rich lean knob on the air box kept turning itself out to lean due to vibration...

 

[2manband]

Re: 1981 Evinrude 25hp Project Motor

So I took her out for a test run on the river today, runs like a champ at full idle, then when warmed up, if I let off throttle it dies in low speed. Then its a big hassle to start it back up. Got it running again, but it was very 'boggy'. Died if I tried to open it up too much...is this a carb issue? I saw fuel leaking from the bottom of the carb, so I headed back to the dock and called it a day...what gives?
I also want to mention that the low speed, rich lean knob on the air box kept turning itself out to lean due to vibration...

Sounds like the carb is coming out of adjustment and running lean. Probably a little richer and/or a little faster idle would solve the bogging/dying problem.

But - I think you'll have to rebuild the carb. The seal around the low speed jet is probably shot, which is causing it to vibrate loose. This could also allow air to leak in and lean out the mix. I don't think fuel would leak out via the low speed jet, but it probably would from the float bowl seal (or possibly elsewhere).

In any case - get a carb rebuild kit and replace all the seals, etc. I bet that solves the problem.

 

[vinmega]

Re: 1981 Evinrude 25hp Project Motor

ok, I will order one and keep you all posted!

thanks!