To all the outboard mechanics out there

[medic]

Hey fellas..

A buddy of mine has a 1967 Evinrude 55 hp (3 cyl) outboard that is giving him total fits. Starts up and runs fine until it's warm, then dies. He has replaced the thermostat, rebuilt the carbs, and double checked all water lines to insure good flow. Still doing it. Any ideas?? Also, does anyone know if this model has a "pee hole"? There is no obvious discharge..

Thanks for your help!!

[Satisfaxion_Gauranteed]

This isn't really the same, but I'll toss it out there.

I had an old snowmobile that did that exact same thing. After doing all of the things you mentioned, my buddy told me to change the coil because if the casing around it has a small crack or imperfection, it'll expand with increased temperature and loose spark.

After replacing the coil, it started running like a engine with rebuilt carbs, new fuel filters, premium gas, new plugs, and finally a new coil ;-)

[Tad Pole]

I agree the coil is the next suspect,i believe that many of your part stores can test them for you.but it sure sounds like it has gone bad to me

[shu9265]

Definitely sounds like the coil is the culprit here.

[Nailer]

The nice thing about outboards is there is really only three things that can go wrong. Spark, Compression, or Fuel. Eliminate two and you will have your answer. The compression should be near or above 100 psi, and within %10 of each other. If you can test the spark, it should jump 7/16 of an inch, nice and blue.

As far as the pee hole, many old motors did not have them. If this thing has sat for a bit he should be advised to replace the impeller.

You can get coils and other parts on line much more reasonable than at the marine store.

I've used Iboates.com for these type of parts and had good luck.

[Priority1]

I hate to admit it, but these other guys with their coil theory makes sense. An intermittent problem, or one that happens when the engine warms, is most likely electrical.

[silver one]

Coil could be a good possibility. Nailer mentioned copression. I would deffinently check that. I have a 1950 Johnson model TN that did the same thing. After going threw everything mentioned I pulled the engine apart and found a bad bearing on the crank shaft. I have also had this identical problem on a snowmobile. same thing bad bearing on the crank shaft. They would start up and run just fine until they got warm, then shut off. let sit for a couple of minutes, start back up then shut off after they got warm again. just my expirence with this simialar problem.

[medic]

Thanks fella's.. I'm going down to take a look at it in the morning. Going to test compression and possibly run it if he has muffs..

Thanks again for all your help!

Bill

[Rayman96]

I would have to agree with the coil theory. They do break down after so many run cycles. When it quits, immediately pull the plug wire and check for spark. No spark equals a bad coil.

Chances are the older evinrude had exhaust ports on the backside of the housing and it was common for these motors to discharge cooling water out of these. Mercs had a pee hole and their exhaust was discharged through the prop.

Good luck.

[Dv8oR]

There's alot of could be's.....

Could be coil, could be points, could be power pack (personal experience), the best part is diagnosing it in its failed state (The power pack plagued me do to it would cool off while "diagnosing" and fire back up again!)

Mine was a '73 65 horse Evinrude!!!