1996 Johnson/Evinrude 150 (Looper) - turns over, fires, wont run

[tc80211]

Howdy all,



I'm new to the forum and did some searching and couldn't find my exact issue so figured it best to start a thread. A couple of weeks ago I was out running and probably was a good 3 hours into the day, engine start hesitating on acceleration. was inconsistent so ruled out as maybe some bad gas and went on. The next time I went over, boat would shut off if I tried to advance the throttle over idle. Immediately I thought was a carb issue and had been a number of years since I rebuilt them, so got the kits and rebuilt all 6 carbs. Did not touch the throttle body plates nor the timing. Put back together, fired up in driveway and was able to put some revs on it in the driveway (not too much) but certainly passed the point it would stall out last time, great.



Took her out, ran all day.



Next day, back to square one, and if I could get it over idle, it would hesitate and stutter/stumble bad.

The following day, same thing, except would not go over idle PERIOD. now I'm thinking electrical again, something is either tripping a safety circuit or malfunctioning. About now I should mention what is new on this motor with the last year:

- stator

- regulator

- power pack

- batteries

- fuel lines

- fuel bulb

So back to my troubleshooting. I decided to replaced the optical sensor eye as it was 24 years old. Replaced, engine fired right up, allowed me to put revs on it. Dropped in the water, idled around and then started throttling up. Got onto plane for maybe 45 seconds and then motor shuts off! Im in the middle of the lake today and all the motor will do is turn over, fire, then not actually run. I uploaded a video here to show exactly what happens:

https://youtu.be/uxO-EuzBefM



I am baffled. I turn the key, get a nice roar (is if it's going to run) and then nothing. I have to be missing something. Any help would be huge!



I have compression on all cylinders

Carbs have fuel

VRO pump is pumping and upon opening it up, is not torn up

[boats.net]

Do you have good spark on all six cylinders(jumps a 7/16" gap)? Have you check fuel for water? Have you tried squirting a little gas in carbs to see if will start up?

[tc80211]

Do you have good spark on all six cylinders(jumps a 7/16" gap)? Have you check fuel for water? Have you tried squirting a little gas in carbs to see if will start up?

Yes sir to all. Plugs are new champions with proper gap... Used a spark tester and had my friend back there when cranking and getting spark on all 6. did the gas in carbs. nothing, unfortunately. Also have all new gas. Has a buddy suggest the stator power coil is likely shot. the engine will "run" if I keep the key turned all the way (not engaging choke, just engaging the starter). and then shuts of the second I let go of the key. Very odd, specially considering the stator is pretty new. As is the regulator. But hey, stranger things have happened. Do you know how I can test my stator with a meter to know for sure (since a new stator is not a small cost)

[boats.net]

If you had low output voltage from stator then that would cause a weak spark and you would see spark jumping a wide gap at plug wire. A peak reading voltmeter is the best way to test a CDI ignition, test the peak output voltage of stator, trigger coils and CDI output to ignition coils.
If it will only run while cranking engine over then may have a bad ignition switch. Might try and disconnect the Black/Yellow wire(ignition stop wire) at CDI and try to start it. With that wire disconnected you WILL NOT be able to shut engine off without grounding the stop circuit(Black/Yellow wire). If engine runs then have a bad ignition switch or shorted black/yellow wire.

[tc80211]

If you had low output voltage from stator then that would cause a weak spark and you would see spark jumping a wide gap at plug wire. A peak reading voltmeter is the best way to test a CDI ignition, test the peak output voltage of stator, trigger coils and CDI output to ignition coils.
If it will only run while cranking engine over then may have a bad ignition switch. Might try and disconnect the Black/Yellow wire(ignition stop wire) at CDI and try to start it. With that wire disconnected you WILL NOT be able to shut engine off without grounding the stop circuit(Black/Yellow wire). If engine runs then have a bad ignition switch or shorted black/yellow wire.

tested resistance on stator wires and get between 0 and 2 OHMS.... so stator is toast it seems. I'm reading I should see 40-70 or something OHMS... contacting CDI to see if they will replace, because only 2 years old. or maybe can have it re-wrapped. Not entirely sure.

[tc80211]

Ok. So I messed up my testing. I was testing resistance between the two large yellow wires and getting 0 ohms. However when I look at the orange and orange black, I’m getting 56 ohms which appears to be correct.

so if looks like stator is working. Super. What a pain. Could the coils be bad?

[boats.net]

If you are getting a good strong spark then coils should be ok as well, if have one that's weak or no spark then swap them to see if weak spark stays with that coil.

[tc80211]

If you are getting a good strong spark then coils should be ok as well, if have one that's weak or no spark then swap them to see if weak spark stays with that coil.

The spark is strong that moment I turn the key, but motor still shuts off. Stator seems to be fine. Power Pack is new. carbs are freshly rebuilt. Racking my brain

[boats.net]

Need to check for spark as soon as engine shuts off, You can use a timing light to watch spark when engine is running. Try bumping choke when engine starts shutting off to see if can get it to stay running.

[tc80211]

Need to check for spark as soon as engine shuts off, You can use a timing light to watch spark when engine is running. Try bumping choke when engine starts shutting off to see if can get it to stay running.

The second I release the key and the key returns to the RUN position, the engine is off. Bumping choke doesn't change that. It has spark when the engine makes the noise like its going to run and then it doesn't have spark. My spark test is one that goes between the plug and the lead and has a glass window to visually see the spark, should I be testing the spark some other way?

Here is what happens when I turn the key and release (under normal conditions, turn the key and release and it stays running)
https://youtu.be/uxO-EuzBefM

[boats.net]

It could be still be a bad ignition switch, try disconnecting the stop circuit wire(black/yellow) from CDI to see if will stay running.

[tc80211]

I don’t see a black yellow from the power pack. Just two plugs that go into the top of it. None that are that color. The only black yellow I know of is at the ignition switch. I disconnected and turned the key with same result unfortunately.

[boats.net]

Disconnect the main harness from key switch at the engine, jump starter solenoid and manual choke it to get running. If it will run like that then key switch or main harness is bad. To shut engine just plug main harness back in.

[tc80211]

Disconnect the main harness from key switch at the engine, jump starter solenoid and manual choke it to get running. If it will run like that then key switch or main harness is bad. To shut engine just plug main harness back in.

Not quite sure how to do that unfortunately. So I connected a new key switch I had (just in case) and same result. So with good compression, rebuilt carbs, working stator and power pack, it might just be time to replace the wiring harness... it's pretty much the only thing I haven't replaced! lol

really scratching my head on this one.

[boats.net]

I noticed in the video you were not giving it any throttle, Try giving it about 1/3 throttle and apply choke when cranking over.