150hp Stalling only when warm - Coils?

AJW

Seaman Apprentice
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Jun 13, 2017
Messages
44
Hi,

I am looking for a place to start with a stalling issue I am having with my 1992 Johnson 150hp. The engine is new to me and has good compression. I have taken it out two times so far and each time it has run perfect until the end of the day after a long idle.The ball gets hard when I pump it, and does not collapse. The most recent time I was probably around 1300rpms when it got rough and stalled, the first time I was at much lower rpms, around 900 and it just cut right out but it was at almost the exact same spot in the harbor. I am able to start it back up fairly easily but it stalls again. I don't think it is the fuel pickup pump because I replaced that with a new (used) one in between the two trips. I have seen some topics from people who have had issues with coils after the engine heats up, but was wondering if there was any other places you guys would suggest I start looking?

Stator? I hear the issues would happen at higher RPMs.
Power Pack?

Thanks
 

Eliza Lake

Recruit
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Jun 22, 2017
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1
HI I have a 1992 evinrude 28slt outboard. It would stall out at high speed last year and this year it stalls even at low speed. I hired a outboard motor repair man to come to our lake and work on it... He first said its not pumping enough water, so he thought its heating up and stalling. We replaced the water pump. Same problem so we rebuild the carb. Same problem but ran some better. Then he said lets replace the fuel line from the tank to the motor, did that with Evindrude 3/8 line complete with new ball. Well it runs now for about 5 to 6 mins and stalls out again. I'm out $748.00 and still have a problem. He cleaned the filters and adjusted the carb while he was putting it all back together. Any Ideas ??
 

AJW

Seaman Apprentice
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Jun 13, 2017
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44
I'm not sure Eliza, but that sounds like a different problem from what I am experiencing and may be worth it's own thread. Maybe fuel pump related?
 

Little Richard

Petty Officer 3rd Class
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Jun 9, 2017
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78
You can try getting an open air adjustable gap spark tester. Set gap at 7/16. On muff check all spark on all each cylinder while cold. If strong and consistent take a hair dryer and warm up your power pack see if it starts acting up. Coil packs too. Also when it's acting up pull plugs and see if they are wet with fuel or dry. If you want to truly check voltage on stator, timer base and power pack you'll need to buy a DTV adaptor for your voltmeter. Google cdi electronics trouble shooting it has a whole series of test . Also while plugs are out see what condition they are in
 

AJW

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Jun 13, 2017
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44
When it stalls have you taken gas cap off to see if it's building a suction.


I have not checked the gas cap, but I did not have this problem before with my other engine (same one) and the whole fuel system is relatively new so that would be surprising. I ran it for a few hours last night and only had this issue at the very end. Would the lock up in the fuel system build up over such a long period of time? Also, fuel pours out of the vent if I overfill it, so would that rule out a sealed tank?

The plugs are new. Great idea with the hair dryer. I am going to try that when I get home. I need to test the spark as you suggested as well. Time to bite the bullet and buy the tester.
 

AJW

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Jun 13, 2017
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The exhaust ports are not submerged.

There is a new development to this issue as of yesterday. As I mentioned, I have had this engine for only about a month. When I bought it the guy compression tested it at the shop and all the readings were in the 110 range. Yesterday I rented a tester from autozone just to double check and the compression on all cylinders were at or just around 65. Is it even possible for all 6 cylinders to go bad in just a month's time, when the engine is running great? (except for these hiccups when hot)

I replaced the coils yesterday and next I need to check for spark. I wasn't able to get a hair dryer unfortunately.
 

Little Richard

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Jun 9, 2017
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78
I'm wondering if that gauge is wrong. Is motor getting proper amount off oil. Is it overheating. Is motor getting to hot to hold your hand on heads. The open air adjustable spark tester would be where I'd start if this compression and possible overheating issue is not an issue. It cost 8.00 at auto store. I'd definitely get another compression tester and check again. When the guy at shop tested was motor warmed up. Cause pistons and what not do expand and would create better compression. But while cool that compression isn't good at all.
 

AJW

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Jun 13, 2017
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44
I'm wondering if that gauge is wrong. Is motor getting proper amount off oil. Is it overheating. Is motor getting to hot to hold your hand on heads. The open air adjustable spark tester would be where I'd start if this compression and possible overheating issue is not an issue. It cost 8.00 at auto store. I'd definitely get another compression tester and check again. When the guy at shop tested was motor warmed up. Cause pistons and what not do expand and would create better compression. But while cool that compression isn't good at all.

First of all, thanks for replying Little Richard. I appreciate it.

I am also wondering about the gauge. The motor is getting the proper amount of oil because I premix 50:1 and have disconnected the VRO. Even after running the motor was not getting too hot to hold my hand on the heads, and it is pissing cold water.

When the guy tested the compression at the shop the motor was not warmed up much, we ran it for a few minutes but nothing crazy. The engine was cool when I tested it yesterday and got the low compression readings.

I'll get the spark tester today when I return the (hopefully defective) compression tester and report back.
 

motoman

Seaman
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Jul 5, 2011
Messages
56
I am not a expert but since I have 150 Fast Strike I will give you a opinion . You stated that it ran great all day but after a long idle that it runs rough and stalls . It sounds like to me that it is simply loading up or fouling the plugs if you will . When you get into the larger outboard I learned and read that they run best when they run at higher rpm's . I troll alot when fishing and mine will load and die , I discussed with mechanic and he suggested when trolling and idling for long periods to make sure that the engine is level as possible and sometimes that helps . Alot time of times I go to neutral and just give it some slight RPM's to keep it cleaned out .You might give that a try
 

Little Richard

Petty Officer 3rd Class
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Jun 9, 2017
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78
I also believe this is very possible. Once your done trolling wouldn't hurt to open her up and burn off that excess fuel and oil. Still would be good to know your ignition system is good as well as compression.
 

Fed

Commander
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Apr 1, 2010
Messages
2,457
Make sure the primer solenoid valve is not leaking & passing extra fuel to the motor when it's supposed to be shut.
Remove one of the output hoses & check for leakage from the valve while hand priming or while the motor is running.
 

AJW

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Jun 13, 2017
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Make sure the primer solenoid valve is not leaking & passing extra fuel to the motor when it's supposed to be shut.
Remove one of the output hoses & check for leakage from the valve while hand priming or while the motor is running.

Ok so I double checked with another gauge and got 75psi compression on all cylinders... Am I dead in the water? It doesn't make sense to me that it would run well like that but I am far from an expert.

Fed, I checked the primer solenoid and it leaks when I choke the engine while primed. I'll check the output hose when I get home. Good idea, maybe the heat is causing it to overfuel and flood the engine.

Motoman and Little Richard. That's possible, I'm interested in hearing your thoughts on the compression as well. I read somewhere on this forum that "it's normal for these big sixes to compress 60-90psi" So I'm hoping I'm ok. I am going to take it out on Wednesday to check to see if changing the coils did anything.
 

valvebounce

Petty Officer 2nd Class
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Mar 18, 2014
Messages
102
Could be your thermostat,or a slight restriction in your cooling system flow.Idling or trolling lets the motor heat up,you could be close seizing the motor when it cuts out.If your compression is down,the partial seizures will have worn your rings.I hope not,but it's worth considering.
Running at higher speeds keeps the motor cooler.
 

valvebounce

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Mar 18, 2014
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I had an overheating problem with an Evinrude,I removed the stat and found the water passage right next to the stat had partially blocked,I cleared the blockage and replaced the stat,it solved the problem.
 

oldboat1

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Apr 3, 2002
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9,598
It sounds like you have a permanent tank. When backing down coming into the harbor, you change the angle and may be picking up some water or other contamination in the tank (down at the bottom where the intake is). Draw some fuel up from the bottom, and let it settle out in a glass jar. Any water will be at the bottom. Also, the used fuel pump can be a good way to go, but you might want to get a kit and rebuild it. If the diaphragm is past its prime, you may be periodically having problems.
 

AJW

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Jun 13, 2017
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Valvebounce and Olddboat, good suggestions and I will look into an overheating issue. The telltale flow is strong and not warm but broken up into 2 streams so it's possible there is a blockage in there. However, I had an overheating issue on a previous motor, the same one, and the issues I am having with this one do not seem the same. There was a limp mode where the engine would power down and this one is just cutting out. The stats were also removed when I bought it, but I replaced them immediately with new ones. would that affect compression? I'd be surprised if there is water in the tank - it is only 2 years old... but who knows.

I can definitely rebuild the pump. The kit is cheap enough, but I'd really like some more advice on the compression before sinking more time and money into the motor. Would you be concerned with 75psi on it all around? I've read that it can be okay on these specific engines, but is obviously way low for a typical outboard.
 
Last edited:

cfauvel

Chief Petty Officer
Joined
Aug 16, 2005
Messages
645
do you have the OMC manual for this motor?

if you do, search the section for recirculation system in section 2 and follow the tests to make sure that is all correct.

the primer solenoid outlet should only pee when the KEY switch is pressed in OR when the red knob is in the UP position...SO with the knob in the down position, pump the primer bulb hard and remove one of the tiny hoses from the primer solenoid to see if fuel keeps coming out...it should not.

how does the motor idle in gear in water initially? if it idles fine and smooth then I would agree that extra fuel is adding up somewhere, hence why I'm pointing you to recirc system (IF this motor has one....I don't know for sure.....I don't have your manual....I suspect it does).

also when was the last time you did the link/synch procedure?

give us the exact model number too
 

AJW

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Jun 13, 2017
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Cfauvel, I believe the model number is J150EXENC, and unfortunately I do not have the OMC manual. I can double check the number when I get home, but I picked up this engine to replace an E150EXENC and this one is identical.

The outlet only pees when the key is pressed in, and I have kept the knob in the down position.

It idles great in gear initially, no sneezing or hiccups. It's smooth. It only has problems at the end of the day. The timeline has gone like this two times: Launch - no wake for 4miles, run at speed for about 7 miles, sit for a bit, run back 7miles, no wake for 4miles. It craps out with about 100 yards left before the launch.

Do you know about the compression on these loopers? I have 75psi on all cylinders.
 
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