TOPIC: '76 Evinrude 25 Worth Fixing?

Just joined this forum; looks great. Looking for advice.

The motor on my '73 Dixie 14 fix up project turns out to be a '76 Evinrude 25 mod# 25653E . Long shaft electric start. Weighs about 100lb.

Is it worth fixing?

Apparently, this is one of the last of the points/condenser/small displacement (22 CI) 25's. Looks like it was used hard and put away wet. Pin drive prop. Compression is 100 and 120 psi; upper cyl is low.

While it would be fun to have a period motor on the old boat, I'm wondering whether the cost of parts, etc makes a new motor the smarter move. Seems like the later, larger displacement CDI Evinrude 25's are highly regarded. How about an earlier one like this?

Well, the difference in compression is disturbing, however might be due to carbon in the rings. Or, a good case of overheating! Maybe some Seafoam carbon-cleaner or OMC Engine Tuner spray might help.

You could pull the intake port covers and get a good look at the pistons/rings & parts of the cylinders. The exhaust side of the cyl's will be visible and if there's overheating damage, you'll see scuffing/etc.

OMC made this motor in its various forms for many many years (since the Fifties), so there are a lot of parts out there.

The 25hp was very light for a 25, and a strong runner.

Whether to repair or not would be determined more by what condition it's in now, rather than its age. If the powerhead internals aren't trashed, parts to fix the outside stuff aren't that expensive (points, impeller, gaskets, a few oil seals, etc).

One thing that is somewhat of a "Buzz-Kill" on these is if the forward gear and shift clutch dogs are chewed-up. It'll jump out of gear when underway. Replacements are very $$$.

Fortunately, the gearcase is Old-School split-style and easy to take apart. All it'll cost to pull apart for inspection is some new spaghetti-seal (OMC O-ring) for the gearcase split and some gasket dressing.

If Fwd gear is trashed, you might start looking for another project (or a good parts motor!).

Otherwise, unless the motor's really hammered, it's likely a fixer.

Most of these old OMC's will still be running when all the newer "plastic" motors have long gone to the Outboard Graveyard!

Cheers......ed

Thanks Ed!

I'll follow your good advice exactly.

I have now ordered a gearcase seal kit, waterpump kit, etc and will disassemble/inspect. Also found an OE service manual online, and have ordered. So, I'm counting on being able to fix it up, with fingers crossed.

I particularly like the idea of having a look at the pistons/cylinders before test running, so will remove the "intake port covers" (as soon as I figure out where they are) and have a look.

The engine will only spin over by jumping straight to the starter motor, and then only with the plugs out. Both plugs in, it really strains. Assume the starter motor is weak (or the engine is dragging internally). I squirted some lube in the plug holes before trying, as the engine was readily turnable by hand via the flywheel.

I'll post here what I find.

Thanks Ed!

I'll follow your good advice exactly.

I have now ordered a gearcase seal kit, waterpump kit, etc and will disassemble/inspect. Also found an OE service manual online, and have ordered. So, I'm counting on being able to fix it up, with fingers crossed.

I particularly like the idea of having a look at the pistons/cylinders before test running, so will remove the "intake port covers" (as soon as I figure out where they are) and have a look.

The engine will only spin over by jumping straight to the starter motor, and then only with the plugs out. Both plugs in, it really strains. Assume the starter motor is weak (or the engine is dragging internally). I squirted some lube in the plug holes before trying, as the engine was readily turnable by hand via the flywheel.

I'll post here what I find.

Hope I'm not overstepping the rules here but I'm currently working on the same motor, and my question may end up helping both of us...I'm into re-sealing the gear case. Upon dis-assembly, I notice gray RTV sealer around the spaghetti seal flange and all the screw heads, is this recommended? Also, I'm changing the bottom cover, because the old one had broken skeg, there's no magnet in the used replacement. I pried the mag out of the broken cover, but it will not slide into the replacement cover, is it ok to file the mag down to fit? Also is there any 'timing' or certain position that the gear/clutch dogs & cradle should be in for re-assembly? Thanks...

From my recent delve:

- Use OMC Sealant or Aviation Permatex (I did) on lower unit seal/screws

- Magnet very brittle. Epoxy (just a dab) in place

- No 'timing' marks, but slider assembly per manual (index to shaft, and correct side forward)

I was impressed by quality of this old evinrude. Guess they cheapened 'em up in later years. Seems to run OK in test tank, but lousy idle quality. Fooled with point gap/timing; the timing plate is not "loose", but low speed timing seems erratic. Shows between marks with a timing light at ~ 1500rpm. Carb low speed needle setting ultra sensitive; idle not smooth or consistent. Got it down to specified 650 RPM with test tach, but really ragged. I wonder if timing plate is oscillating? Maybe bad reeds or something? Pistons/rings look OK through intake port covers.

Ran a pint of seafoam through carb mouth; neighboring farmer drove over to see if house was on fire!

I will run behind boat for a couple of tanks before investigating lousy idle further

My post repair takeaways:
22 cubic inch 25Hp; '76 was last year, apparently. Points a drawback; iffy ignition timing. Weighs ~ 90 lbs, which is plenty. Later motors bigger and heavier