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Need some help with a 81 E25RCIM. Lower unit and cylinder isssue

D

Doug Schepp

New member
I have a 1981 Evinrude 25hp with a couple issues. The first issue is that while trouble shooting a planing problem, I discovered that the lowest part of the lower unit (sorry, I don't know the proper term) is bent. Is the area below the gear oil drain screw solid metal or is it hollow? Hoping I can hammer it straight. If I can't get it straightened, does anyone know where a person can find a lower unit for this motor? Not having much luck finding anything online for this model.

Second problem:

Motor will drop to one cylinder at random. Some times it will making a sputter and snap back to full power if I hold the throttle wide open and other times not. Some days (not often) it will run strong all day with out issue.

I'm running straight 87 oct (no ethanol) with a 50:1 mix (I am running a little rich now, but not by much).
- Prior to any trouble shooting I ran a can of seafoam through it, but other than making the full power operation smoother, it did not stop the drop out.
- I have cleaned as much of the carb as I could with out removing it.

- Compression (checked it today) on the top cylinder is 110 and about 113-ish on the bottom (the one that keeps stopping).
- The fuel filter screen is clean and there are no fuel leaks that I could see or smell.
- plug wires are in perfect condition.


Today I cleaned up every electrical ground I could find, inspected all of the other electrical connectors and cleaned as much corrosion as I could with a steel brissel brush I replaced the spark plugs and gaped them at .029. The old plugs were blackened, but did not appear to be fouled...I replaced them anyway just to be sure.

Before I take it back out to the lake to test, can anyone suggest anything else to check.


Thank you in advance for any assistance.
 
The skeg probably will break if you try beating it back. Better leave it alone unless it is really, really, really bent. But they usually break off before getting that bad.
 
fdrgator said:
The skeg probably will break if you try beating it back. Better leave it alone unless it is really, really, really bent. But they usually break off before getting that bad.
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It's about 2° off center, and the brake (actual bend) is below the plug hole. If it is solid metal. I can heat and treat it. I just want to make sure it's not an oil filled cavity. Have never ripped apart aa lower unit so I don't know what I'm looking at.
 
It should be solid cast aluminum at that point. I straightened mine by using 2 hammers, and a block of hardwood. I wouldn't recommend heating it, you'll likely break it off for sure then. Just work it back into shape gradually, using one hammer (and the hardwood) as a dolly on the opposite side that you are beating on.
 
bill_w said:
It should be solid cast aluminum at that point. I straightened mine by using 2 hammers, and a block of hardwood. I wouldn't recommend heating it, you'll likely break it off for sure then. Just work it back into shape gradually, using one hammer (and the hardwood) as a dolly on the opposite side that you are beating on.
Click to expand...

That gives me something to work with. Thank you.
 
Glad to help. Make sure that you support the side of skeg (that's what it's called) opposite the side you are hammering on. I used a 3 lb sledge, and hit mine with a 16 oz ball peen. And I used the hardwood opposite the hammer once it started getting straight. Don't get carried away, take your time, and it will straighten. Don't wallop it too hard. As to the cyl dropping out, I'd suggest that you pull the carb, and give it a rebuild. Get a rebuild kit, and use it.
 
Just an update. I changed out the plugs and found that the old ones were not gaped any where near factory spec. I also cleaned up all of the electrical connections. Took it out to the lake for a test run yesterday and the motor ran like a champ.
 
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