OMC 3 cylinder "loopers"

[amuller]

So would you advise the QL or the L plug for use now? The "j" gap means the short ground electrode?

I’m an admirer of the ignition used by West Bend on its inline 4s. One cam lobe, four point sets spaced at 90 deg, 4 condensers, and 4 coils. So damn simple and hard for it all to fail at the same time as long as there is juice. Maybe there is a reason Chrysler didn’t keep it? Strong desire to go pointless?

I think I have a pump and set of tilt cylinders off a little Renault Mercruiser. If I got motivated I think I could gin up a bolt-on power tilt setup with that. It would be only tilt though, not trim.

[frankr]

I suppose either one would be ok. The L77 has pretty much been superseded by the QL anyway. The numbers—they make little sense. Back in the day, it was L77J4J, with the cut-off side electrode. Then they renamed it L77JC4, then added the suppressor and it became QL77JC4. My 1984 35hp came with the QL and they work great. In fact, if I were to pull one out right now, it probably would look like a cat crapped on it, but no matter they still run. The CD ignition will fire right through the cat crap. Yeah, I do a lot of slow speed running on rivers and creeks, hence the cat poo.

[amuller]

Modern car ignitions can fire almost any plug, even one burnt down to a stump. I suppose outboard ignitions should be the same. Quick rise time, high energy … as long as there isn’t a metallic short across the electrodes. you get a spark. But not all CD ignitions have these qualities. I don’t think cars are usually CD.

[amuller]

Initial checkout:

Plugs found NGK B7HS10 Is this a good plug for these motors?

Compression top 142, middle 155, bottom 144. Not quite as even as I’d like.

shift solenoid ohms about 6.8, amps about 2.3 (each).

Gearcase fluid seems to be conventional thick stuff, not the thinner stuff called for, plus had maybe 1/3 cup water. No sign of rusty material.

But, on my other one the prop can be rotated counterclockwise freely, with a snapping action. This one is locked in gear. I’m wondering if the shift piston might be stuck. I am not totally clear on the internals of these.

Control box seems OK but the interlock parts for the shift pushbuttons are missing.

Haven’t checked ignition yet. It has a newish-looking CDI amplifier box.

We shall see…..

[frankr]

Just going by the picture, it looks like the clutch dog has conventional ears. In other words, non-ratcheting. If that is the case, it should be in forward (by default) and the prop should rotate back and forth somewhat.

[amuller]

Looks like that to me. The pics of the 72 are not as clear, but the parts are different, so maybe they are supposed to behave differently? Likely I won’t know until I try running it, or at least cranking it.

I also noticed the starter shaft (American Bosch) is bent. Wonder how that happened. Maybe someone put a tool behind the pinion to hold the flywheel for nut-tightening?

[fleetwin]

Yeah, I don’t think the 3 cylinder gearcase has the ramped clutch dog, so what you are experiencing is normal..Don’t know what to tell you about the starter, does it crank the engine OK? You will want to drain/refill that gearcase a few times with fresh premium blend to make sure it shifts correctly. Don’t know what the shift solenoid current draw should be, did you check them with an ohm meter? The compression seems fine to me….

[amuller]

I drained and filled with tractor hydraulic fluid (I have a five gallon pail that literally fell off the back of a truck; use it for flushing….). The gearbox seems to shift properly at manual cranking speeds, So far so good. Will refill with the right stuff eventually. It’s gotten expensive.

The starter seems to work OK so I’ll leave it alone. Attempts to straighten things like this sometimes cause new problems, at least at my skill level.

Next is to check the amplifier box, go through the wiring and service the points, water pump, thermostat.

[amuller]

The existing electronics (CDI replacement stuff) give a nice hot spark, so I expect this motor will run after the points and carbs are serviced.

I have heard of people using MSD automotive ignition boxes on these motors. Anybody have experience with doing that?

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