"Newer" 25/35hp OMC compatibilities

[johnyrude200]

I did purchase that, the guy coincidentally lives 5 mins away from me, but that aside, I can manufacture these for future motors as needed as 1/16th sheet stainless steel is pretty inexpensive, and these things are less than a 1/3rd square foot, so I’ll buy some to replace these.

I feel a little safer starting with new rather than trying to refurbish something that is already stretched/warped/bent, and 40 years old to boot.

Are you going to be up at either my meet or the madbury meet these upcoming weekends? Should be a good time at both!

[dan-in-tn]

If we haven’t lost everyone off this thread, I wonder if a little thicker baffle plate might be wise? Say 3/32"? You can bet OMC went with the minimum. Are the later plates any thicker? Just wondering if thicker might make them a little more stable to the usual running temp. I would be interested in anyone else’s take on this. It won’t cost you that much more to make it a little thicker and the bolts won’t even have to be longer.

Dan in TN

[johnyrude200]

I was thinking the same thing, even 1/8th. The stainless plate metal I can buy steps up in small increments, obviously the price goes up with the thickness. My only reservation is if I have any jigsaw blades that can cut through stainless plate. Fortunately the baffles are pretty square and there is plenty of clearances around if I were to cut it larger than an original, but I’d like it to be pretty close to the original dimensions if possible.

It’s not a difficult shape to cut out.

In terms of thickness, I have found at least 3 different versions so far in the post ’79 baffles. They actually were thinner than the original pre ’79 ones. The newer ones, however, have folds/cups in them and that alone would provide a huge amount of extra strength, despite being thinner.

Plus the area that is actually being hit straight on with exhaust heat is about 1/3rd the original, and there is a lot more water being circulated through not just the bypass plate, but also the cylinder jackets. I suspect these were all revisions to address this exact issues.

I think with anything pre ’79, a thicker plate is about as good as you’re going to get to stop this issue from repeating (unless, of course, the motor gets severely overheated from a clogged intake/bad impeller/stuck thermostat/etc).

[collectorinspector]

Something for everyone here.

https://www.youtube.com/watch?v=dsncYOF … uscomments

The plate was warped as yours initially. I fixed it as described above. Somewhere in the vid it shows how it went back together.

It also shows how to be happy with gallery cleaning etc.

I have not done a vid regarding the transfer cover service but same attention to detail is required.

Covers off every 5 years regardless.

Regards

B

[dan-in-tn]

Nice looking motor and you can sure tell someone is doing regular maintenance. That would probably help any of these pesky engines, but that seems to be a lost art here in America. Except for us mechanically inclined the rest of America just goes out and buys more! Like I have said throughout this post, the cooling system (all of it) requires constant attention. Not just an impeller once in awhile. That motor sure brings back memories (nightmares actually). Getting a little too close to 1976 for my good. Thanks for the vid and music.

Dan in TN

[johnyrude200]

Update on my motor. So it’s pumping water great…but not at idle (telltale looks normal at all RPM ranges…absolutely wasnt before). Experience tells me the aluminum baffle is doing OK but exhaust gases are still getting into the water jacket, probably 50% less now after repair, but with that screw missing, despite the gasket sealer, the PSI of the exhaust is pushing it’s way in.

Ill report back after I try out another idea (smile).

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