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.
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.