1974 25hp exhaust cover plate leak

[tinkertinker]

I have a new to me 25hp 1974 Johnson.

Runs very well, but water is leaking profusely from what I think is the exhaust cover plate (port side of head). One bolt is pretty rusty, has a drip, but more water coming from lower part of seal, it seems.

2 questions:
1)How serious is this?

2) where the heck can I find a parts diagram for this motor? I am hoping I just have to replace some gaskets but can't find part numbers to order them. From iboats, of course.

This has no telltale, but decent warm water flow is coming from the exhaust holes on the leg. I can touch the cylinder head even after running. Hot, but tolerable.

thanks!

 

[Daviet]

Re: 1974 25hp exhaust cover plate leak

Go to the mfg website, punch in your model# and you can see a parts breakdown.

 

[tx1961whaler]

Re: 1974 25hp exhaust cover plate leak

1. Serious. Fix it ASAP


2. http://shop2.evinrude.com

The issue isn't really about it not cooling, or water running down the outside of the engine; it's the possibility that water is getting into the pistons through a leaky inner exhaust plate.

 

[tinkertinker]

Re: 1974 25hp exhaust cover plate leak

Found the correct part #s for the gaskets on another site, though evinrude.com only had a pic of the part and schematic #, no part number.

Guess I've got question 2 answered!

 

[tinkertinker]

Re: 1974 25hp exhaust cover plate leak

thanks Whaler.

guess I won't know if it is gaskets only till I get those bolts out. May the bolts come out!

 

[tx1961whaler]

Re: 1974 25hp exhaust cover plate leak

thanks Whaler.

guess I won't know if it is gaskets only till I get those bolts out. May the bolts come out!

I won't tell you how many I broke last time I took mine off.....

If you break any, don't be tempted to try an EZ out extractor. It will just snap off and then you'll have serious issues. I just drilled out the broken ones using the exhaust cover as a drill guide.