1996 Evinrude 15HP Stuttering/Surging approaching & at WOT

[mkau3024]

Hi all,

Wondering if anyone might have any advice for me. I have a 15HP Evinrude (E15REDS) that started stumbling at WOT last time out a few days ago. I replaced the spark plugs but no improvement. Tonight it was sputtering approaching WOT and then sort of surging when I did get there. Fuel is fresh, I'm out with it all the time and it usually runs great. Very smooth reliable motor.

I inspected the tank, fuel line and connections but didn't notice anything obvious. I am including a link to a video I took this evening. Any thoughts or ideas at what I might look at? Do you think this is fuel related, or electrical maybe? I also ran it with the cover off and it was the same.

Thanks in advance for any suggestions!

15HP Video

 

[saltchuckmatt]

My guess, fuel related. Sucked up some crap. Could be electrical though....so you need to count out one first. Id pull or flush the carb.

Did you check to see if it was staying cool? Just because it's peeing doesn't mean it's cooling.

 

[mkau3024]

My guess, fuel related. Sucked up some crap. Could be electrical though....so you need to count out one first. Id pull or flush the carb.

Did you check to see if it was staying cool? Just because it's peeing doesn't mean it's cooling.

Thank you for replying. It did not seem to be running any hotter than normal. That will be my next step, pull the carb, look at all of the fuel related components much closer. I'm not as good with electrical troubleshooting.

 

[saltchuckmatt]

Well, we can walk you through that too if needed.

Sometimes I remove the float bowl drain screw, and the idle circuit screw and blow a little bit of carb clean in the idle hole. Then I pump a bunch of gas through the bowl and let it drain for bit. A couple of jiggers or so.

If you have just a spot of junk that might be all you need, if not than you will need to inspect the inside of the carb.

 

[mkau3024]

Update... pulled carb off and sprayed with carb cleaner, disassembled as much as possible, ran wires through all orifices, reassembled, replaced the gasket behind it (was somewhat worn) and tightened everything back down well.

Took fuel pump off too and disassembled/checked parts, no obvious issues. Reassembled and tightened everything down.

Emptied gas can again and replaced with new gas mix.

My original video expired so I'm posting that one again, and another.

15HP from original post
15HP update video

Seems to idle and run better than before now but the original issue remains. May replace the fuel line and fitting today. May also check the impeller.

Any other suggestions welcome.

 

[racerone]

It clearly sounds like an ignition issue to me.-----Could be a bad plug or bad plug wire.

 

[mkau3024]

It clearly sounds like an ignition issue to me.-----Could be a bad plug or bad plug wire.

Thank you. I replaced the plugs already, that was my first guess. I made sure the connections were all tight and the wires looked ok, but I guess you can't always visually pinpoint the problem. Could it be the coil assembly itself? I replaced the power pack last year for an issue I was having then and it's been running great since.

 

[cyclops222]

I would do the WOT run and allow the engine to do the steady missing routine for about 30 seconds. Then slow down RAPIDLY and immediately stop the engine. Pull each plug out. Look for oil wetness. Black stuff deep inside the plug. Any difference between the 2 plugs is a strong clue to a sparkplug power pack if they use them for each plug............
IF IF the plugs look TOO CLEAN? Then a head gasket may be starting to leak. Check all the head bolts with a TORQUE Wrench. You may find 1 or more bolts getting loose with age.......... DO NOT tighten any hot bolts. Wait for a cool down engine condition.
The sparkplugs SHOULD show a problem in each cylinder at WOT

 

[cyclops222]

I listened to you run it again You are Teasing the WOT setting. I saw the throttle being slightly moved back and forth a smidge. Hold the throttle twist against FULL POWER position for 15 seconds.

 

[racerone]

Run with a timing light 1 cylinder at a time.------Observe the light.

 

[saltchuckmatt]

Not sure you completely cleaned the carb correctly but try this.

In a barrel, run the motor at night and look for some flashing off of the coils or coil wires. Seems like it's arcing.

 

[mkau3024]

Thank you all. I did buy a new fuel line and connector today, and although the fit seems much tighter, they didn't make a difference either.

In the second video, you're right, I didn't have it wide open. WOT it was still bogging and surging, at 75% it was kind of stuttering/popping so I was trying to show that. The sound didn't really translate well in the video.

Unfortunately I have to go out of town for work in the morning and won't be back for a week. But I really appreciate all the input.

I'm not sure on the carb either, so I might have another go at it when I get back. I will try these other things as well. I hope you all enjoy the rest of your weekend.

 

[racerone]

Wrong powerpack ?----Part # on your powerpack?

 

[mkau3024]

Wrong powerpack ?----Part # on your powerpack?

Powerpack is the correct part, but the problem was indeed at the powerpack.

Took me a bit to get back to this after being away, but it came down to a loose/corroded ground connection. There was an old rusty star washer stuck to the head there (from before I replaced the powerpack I'm guessing) and I must not have tightened the lower bolt down enough as it eventually loosened enough to move around. The issue progressed to where I could see it arc there occasionally, even at idle, so I was finally able to pinpoint.

Once I cleaned things up and tightened back down, running better than ever!

Thanks all. I really appreciate you taking the time to post suggestions.

 

[saltchuckmatt]

Nice example of how it doesn't take much corrosion.

Thanks for responding.