Lower Unit Seals 25 hp Evinrude

[leejacstu]

I have a 1976 evinrude and the lower unit is leaking around the propeller, and there is oil accumulating on the stabilizer. I think I can put new seals in the lower unit and do a pressure check if I had a manual. Where can I find a good repair manual for this repair?

 

[samo_ott]

Re: Lower Unit Seals 25 hp Evinrude

Ken Cook... but I think the name changed... oh well... someone else will respond.

 

[leejacstu]

Re: Lower Unit Seals 25 hp Evinrude

I found a SELOC manual that covers 1971 to 1989 models from 1-60 HP. I question if a manual that covers this much range can really be effective. Anyone that can provide comment please advise.

 

[HighTrim]

Re: Lower Unit Seals 25 hp Evinrude

I would not reccomend that manual, for the exact reasons you stated. You need a factory OEM service manual, check ebay or outboardbooks.com for a factory reprint. I would check ebay first since it will be a bit cheaper.

Also are you positive that your lu is leaking? Positive that what you are seeing is not carbon (ie fuel oil) mixture. That is quite normal. Have you checked the lower unit fluid first to ensure that it is low, or milky white, indicating water intrusion?

The water is heavier than the oil, so watch for the first bit that comes out, if it is milky white, than you do in fact have water intrusion.

The drain and vent screw gaskets are the number 1 spot for water intrusion. If in fact you do have a breach, I would change the oil with a full synthetic, as well as change these gaskets. Run the motor, then check again for water, if there is now none, you are good to go for under 10 minutes work and about a buck.

 

[HighTrim]

Re: Lower Unit Seals 25 hp Evinrude

If you do find to have water intrusion, you can pressure test as stated below, or simply re seal the entire lu as per your new manual.

To pressure/vacuum test a lower unit:

a) drain the gear oil
b) use an appropriate adapter with a gauge tee'd in to apply pressure or vacuum. No more than 15 psig for pressure. You can use a bicycle pump or any other compressed air source for pressure. For vacuum, you need a vacuum pump.
c) LU should retain some pressure or vacuum for 45 minutes minimum.
d) If pressure doesn't hold, submerge LU in water to find leak source [possibilities: drive shaft seal, prop shaft seal(s) (usually two), shift shaft seal and the fill/drain screw washers.]
e) replace offending seal(s) as required.

 

[HighTrim]

Re: Lower Unit Seals 25 hp Evinrude

This is what you want here, at a great price. I would get this one ASAP.

"http://cgi.ebay.com/1976-Evinrude-Outboard-Motor-Service-Manual-25-HP-L_W0QQitemZ140185859256QQihZ004QQcategoryZ423QQrdZ1QQssPageNameZWD1VQQ_trksidZp1638.m118.l1247QQcmdZViewItem"

 

[leejacstu]

Re: Lower Unit Seals 25 hp Evinrude

I missed the opportunity on the manual but I will continue to look for an OEM manual.

This engine sat up for five years, on its head no less. That's a long story but I bought this engine at a good price. It started the third time I pulled the cord and runs really well. I think if I get the oil problem solved it will serve me well. I have had this engine in the water three times, and I pulled the prop out of the water when it wasn't running because of the oil leaks.

I pulled the drain plug and there is not any water in my lower unit. I am finding oil in three places.

1. A very small amount is dripping out of the center of the prop. I feel certain this is a leak. Could I be wrong?

2. Oil is accumulating on the cavitation plate. The oil is very clean and thick, just like gear oil. Where do you think it is coming from?

3. There is a very small amount of oil (very dark, and barely enough to measure) dripping out of the top of the motor through a drip hole, and down the shaft of the motor on the left side. I don't think this is from the lu, but I hope its not a sign of serious engine trouble. Your thoughts?

Matthew

 

[wbeaton]

Re: Lower Unit Seals 25 hp Evinrude

That's a very simple lower unit to work on. I have a factory manual for a 1970 20 hp I can email you. It shares the same lower unit. PM your email address and I'll send it out.

 

[leejacstu]

Re: Lower Unit Seals 25 hp Evinrude

Wayne,

I just sent you my email address. Are there any special tools involved with this repair? This is my first lower unit repair so what I don't know is a lot.

Matthew