outboard issues - intermittently loses power

[bare foot wader]

Johnson 90hp 2 stroke, model year 1997 if I remember correctly....a few weeks ago I would intermittently lose power, rpms would drop and boat would lurch forward, just for a second and then back to normal...would happen 3-4 times in a day....since I owned the boat I had always used ethanol free, but due to change of ownership at local gas station and living remotely, I had to use E-gas for about 4-5 tanks early this year...initially figuring a fuel issue, or something clogged, I drained the gas and filled with shell 91...and I regularly use seafoam with each fill up...I think I remember the owners manual saying E gas was ok to use though??

 

same conditions continued for 2 weeks, starts up fine, runs fine and then randomly RPM's drop 400-1000 and feels like the o/b is stuttering for a few seconds and then back to normal....if I backed off the throttle that didn't really help anything...so whenever it acted up, I'd come to a stop, and rev it up with the high idle button pushed in...figuring maybe that would clear something out...it would resume back to normal operation

 

the issue got really bad after 3 hours of boating last weekend, complete loss of power, feels like the engine is stuttering/slipping, throttle at wot and barely any power...I stopped using it immediately and finished the day with my kicker

 

towed to the nearest shop and after a week they can't figure anything out, they've just told me everything is OK, they cannot produce my symptoms and they aren't able to test under load in their shop apparently and nearest lake is 1.5 hrs one way....said their techs will spend a bit more time on it this morning but basically they didn't find anything wrong

 

any ideas on this? anybody had similar issues? or anything to bring up with their techs? if it's not a fuel issue, maybe electrical? which I know nothing about

 

compression tested and ok, spark plugs ok, hub is ok (I think rpms should spike with a spun hub, not drop), fuel filter replaced....if they didn't find anything, not optimistic about my next day on the water...thanks for any feedback

 

[DRIFTER_016]

Sounds like and electrical issue.

Did you replace the spark plugs?

Had an issue with a plug a couple of years ago where it was cutting in and out. Brand new plug was defective.

Could be a coil pack or a loose connection in the ignition circuit.

Check ignition wires as well.

[bare foot wader]

they said plugs were ok today, but maybe I'll ask for new plugs for piece of mind...thanks

[BillM]

I wouldn't think the plugs would cause this. Almost sounds like the coil going out.

[dracokaos]

Another thing to check is your fuel lines. Make sure not cracked. It may be sucking air.

 

Cheers, hope you get it figured out

[fishnsled]

I had something similar going on with my motor this spring. (running at WOT the motor would cut out intermittently and then run OK) Cliff took a video and we sent it to Bernie and his first thoughts were a possible coil going. (Actually started my last trip last fall and thought it might be plugs. Put new ones in this spring and the problem was still there.)

 

I was fortunate enough to be going to Bernie's soon after this and he brought out his timing strobe and we went for a ride. After checking all the wires/coils the problem was on all of them. He started moving the wires on the motor around and found pushing them one way and all was good but when pulling them the opposite the motor would act up. Went back to the dock and he found a terminal had broke with 3 wires going into it. He saved as much of the wire as he could and put on a new terminal, bolted it back onto the motor and that was all it was. Been out a few times since and the motor has run perfectly. Could be as simple as a bad wire somewhere, maybe a coil.

 

Take some video your next time out and show that to your repair guy if it is still acting up. If you have someone with you on the next trip, take the cowling off and go for a ride and do the wire wiggle test and see if that gives you some answers. Better yet, check all your wiring before you head out. My broken connection was a bit hidden.

[landry]

I had bad coils and it was similar.

Sounds like they checked fuel related issues.

I have always found Bay City marine to be awesome and they will water test it.

Landry

[workwear]

i had the same problem with my motor bout 4 yrs ago....it was a simple fix

 

my battery terminals were loose....

 

might wanna check that!!

[ecmilley]

Sounds like a bad power pak to me. Almost text book failure drops a cyl or two when hotm

V4 90hp?

[bare foot wader]

yep, v4 90hp...and yes, runs great for the first 30 mins or so then starts to act up, and progressively worse and worse

 

battery terminals tight, batteries well maintained over winter...my untrained eye checked all the wires/connections but I certainly may have missed something obvious

 

I'll see what the shop says tomorrow, thanks for the tips

[smitty55]

Does it run ok again now that it's cold or is the fault constant now? In which case the fault should be much easier to find.

I'm not a marine technician but from what you describe it seems to be an ignition/electrical fault that is being exasperated by heat. I would first eliminate all the mechanical connections just to get them out of the way. You've done that. Then pick up a can or two of freeze spray. Assuming then it might be an electrical component like a powerpack, or coil,or relay, if you can get it to fail again then shut the engine down and spray the components and see if the fault goes away. It's pretty cheap troubleshooting compared to what a shop will charge you per hour.

Good luck with it. Cheers

[bare foot wader]

shop has the boat now, they called this morning and said they had it running for 30 mins or so and couldn't produce the symptoms I listed, talked about what was happening in more detail and haven't heard back yet...will follow up tomorrow

[John Bacon]

Was it raining or damp when you were having the problem? I had an issue with an older engine losing power; the shop couldn't replicate it.

 

On one of the very few sunny weekends we had that summer I clued into the fact that is only happened on rainy days. The shop couldn't replicate because it never rained in the shop.

[Old Ironmaker]

A bud had the same thing this spring. It was the powerpac. I'm no expert on marine dealers but where is a marine an hour and a half away from water in Ontario? Not many places that far from water in this province. I see your locations are from BC to TO. If you are in the London area I would take the drive to Simcoe and see Mr. John Hayington at Proctors in Simcoe. More than once he's troubleshot a problem for us over the phone when no one else could find the problem. They regularly will take the vessel to Dover to field test it if shop conditions don't replicate the problem. Big difference between a shop and a lake.

[Fish Farmer]

#1

While the motor is running and warmed up, tap the Power Pak lightly with the handle end of a screwdriver. If the motor flutters, Power Pak.

#2

Since Ethanol gas, Ethanol has caused deteriorating of internal parts and certain hoses, thus clogging carbs.

Just a tip.

[DanD]

My 40 Honda had less then 30 hours on it and it began to stall out when the ambient temp was above 25C. Pull the hood off let it cool for a few minutes and it would restart & run perfect; ended up leaving the hood off for the rest of that day. Being that I had a shop manual for the the motor and a test chart for the Electronic Control Unit (ECU); I thought I'd try and trouble shoot this myself before taking it in for a warrantee claim. The problem was to get the electronics hot enough to act up I had to leave everything together and the ambient temp had to be in the high 20's. After it started stalling and by the time I got the hood off and the ECU unpluged everything tested good; it had time to cool.

I ended up taking the motor to Bridge's Marine in Port Dover. They could not even get the thing to stall out for them; not until I told them to put the hood on set the motor in an outside tank that was in the sun. That's when they came to the same results as what I found. They called Honda Tech support told them their findings and the tech authorized a new ECU to be installed. It solved the problem but we still don't know what portion of this $500.00 ECU was failing; I'm just glad it was covered under warrantee.

My point being your repair facility will likely have to reproduce the run time, temperature and load on the motor; which can be a very difficult thing to do.

Here in the automotive trade the the car's computers have the ability to store what is called a freeze frame. This freeze frame shows us all the sensor readings at the time of the fault. With that info we can go out and duplicate the reading and hopefully cause the failure with the test equipment connected. Not sure if today's outboard's ECU have those capabilities?

 

Dan

Edited July 8, 2014 by DanD

[SRR]

Assuming you have an onboard fuel tank, try running with a portable. It could be the check valve in the primer ball or a cracked pickup tube in the tank. I had a motor some years back that exibited the same symptoms as yours and it turned out to be the latter. If you don't have a portable try pumping the ball when it is acting up.