150hp Stalling only when warm - Coils?

[Joe Reeves]

AJ.... Compression varies with the rotation speed at which the engine performs, something to keep in mind. The fact that the psi readings are identical or close sort of indicates a rpm problem.

All spark plugs re to be removed when doing a compression or spark test in order to obtain the highest cranking speed.

Did you perform a spark test whereas a tester would have an adjustable gap to be set at 7/16"? If not do so. Adjustable testers can be found at any automotive parts store... or build the following

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(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4
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Let us know the final compression psi results and also the spark results. NOTE that the 7/16" is important.

Question..... Does this 1992 150hp Evinrude run normally at all speeds, including idle say for the first 20 minutes or so... BUT... has the problem you speak of after the engine reaches operating temperature? A short revival of the existing problem explained here would be helpful.

 

[AJW]

Joe,

Thank you for the response on the compression - I did not take all the plugs out when I did the test...

I will go to autozone today and get the tester for compression and I'll stop putting off this spark test and do that as well. I'll just buy one because I don't want to leave as much room for human (idiot) error.

Answer: Yes, it idles well and runs well at all speeds with no coughing or knocks. It even idles well after reaching operating temperature until it cuts out.

Just to recount my issue: 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. the last time it sounded like this: https://www.youtube.com/watch?v=1HP463ElDAg

 

[Joe Reeves]

I've been jumping back and forth through all of the above posts so as not to overlook anything... BUT... having something escape me is still a possibility. I viewed and listened closely to the manner in which your engine faltered and died... I noticed a build up of smoke just before it stalled, possible just exhaust as the rig slowed down?

You've eliminated the VRO setup and are using premix. I assume you're using the VRO as a straight fuel pump?... and if so, did you convert as follows?
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(VRO Pump Conversion To Straight Fuel Pump)
(J. Reeves)

You can convert the VRO pump into a straight fuel pump, eliminating the oil tank and VRO pump warning system, but retain the overheat warning setup (and fuel restriction warning if so equipped) by doing the following:

1 - Cut and plug the oil line at the engine so that the oil side of the VRO pump will not draw air into its system. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.

2 - Trace the two wires from the oil tank to the engine, disconnect those two wires, then remove them and the oil tank.

3 - Mix the 50/1 oil in the proper amount with whatever quantity fuel you have. Disconnect the fuel line at the engine. Pump the fuel primer bulb until fuel exits that hose with the tint of whatever oil you used. Reconnect the fuel hose.

That's it. If you want to test the heat warning system to ease your mind, have the key in the on position, then ground out the tan heat sensor wire that you'll find protruding from the cylinder head. The warning horn should sound off.
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The stator on that model, unless a change was made that I'm not aware of, would be a 35amp stator that is prone to overheating and encountering a meltdown. When this type failure takes place, the stator, which is the beginning of the ignition system and also the battery charging setup, may perform perfectly when cold... BUT... as it heats up, it will falter and result in weak, erratic, and eventually no ignition/spark.

The stator, again unless some change was made, will have two large black coils at the rear portion of it that generates approximately 300 AC volts to the powerpack capacitor, needed to energize the powerpack. Carefully, closely, visually inspect those two coils to see if they are dripping a sticky looking substance down on the powerhead area, and if so, replace the stator regardless of what test reading you may obtain from it.
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Another possibility..... You say (somewhere above) that the fuel primer bulb does get hard... and does not collapse. This indicates that the ball vales are okay and that a fuel restriction does not exist. I'm wondering about a temporary loss of fuel.... Have someone, when this problem arises, constantly pump the fuel primer bulb, acting as a manual fuel pump. If this action cures the problem... the present fuel pump is suspect. I'm assuming there are no fuel/air leaks as none have been mentioned... that would be quite noticeable. Let us know what you find.

 

[AJW]

Joe, thanks again. I will look at the stator for any dripping when I get home. Can I check that without taking the flywheel off?

I converted the VRO as you suggested above and all the steps were followed.

Keep in mind that the video I posted above was not me, it is just video I found with a similar sounding problem.

I will have better answers for us after I take it out tomorrow. I'll be able to have someone pump the ball and I'll be ready with my phone to record what it sounds like if it happens again. fingers crossed I fixed it with the coils, though.

 

[Fed]

When it plays up get someone else to drive & pump the ball yourself, you know what it should feel like when it's working properly.
Can you borrow a portable tank + hose & primer bulb?

 

[AJW]

Just to keep everyone updated: I just re-rested the compression (cold, all plugs out) and checked the spark. Starting at the top left working down and then working down from the top right I got 81-80-80-82-80-80.

The spark looked strong. I tried to look up at the stator but didn't see anything. I''m not sure if I would be able to see it without pulling the flywheel anyways.

I disconnected an output from the vro, pumped the ball and checked the fuel for water or contamination and saw nothing.

I'm taking it out tomorrow so we'll see if the coils did anything. I figure I'll check that before going too crazy with anything else. I don't have a spare tank and ball to test at the moment.

 

[AJW]

When it plays up get someone else to drive & pump the ball yourself, you know what it should feel like when it's working properly.
Can you borrow a portable tank + hose & primer bulb?

Yesterday I took the boat out to test the fuel system and see if I fixed the problem by replacing the coils. I definitely did not... thanks sea tow...

I was able to have a friend drive while I pumped the ball when the issue was happening and have determined that fuel delivery is not the problem. The ball was staying hard, and pumping it was not helping.

Yesterday the issue got worse, I had a loss of power at speed. I got it going again and once I started idling around chasing birds is died and wouldn't start again. It definitely seemed to get better as it cooled down. I also opened it up to burn loaded up fuel as suggested and that did not help either.

So.. I'm heavily leaning toward the problem being ignition related, and since the power pack looks brand new, I am thinking it is the Stator. Does anyone have suggestions on other potential issues? Can I test that without pulling the flywheel? I Am going to try to pull the stator off my parts motor tonight.

I spoke with the guy who sold me the motor and he suggested I remove the thermostats. He always kept them out and I immediately put them back in and that's when the problems started. thoughts?

I know these engine have a limp mode for overheating and that's not what is happening here.

 

[cfauvel]

You can absolutely test the stator without removing the flywheel...you need either a analog peak reading Mulitmeter, or a digital multimeter with DVA adapter, at least 5 jumper wires to test the various pins.

without the DVA adapter you can test for continuity and OHMs...refer to CDI electronics website for expected values.

 

[oldboat1]

still haven't tested spark? should see approx 1/2 inch sharp spark measure with an open air tester.

If this is a salt water motor, you may have a buildup in the water passages. Removing t.stats (PO) is a signal there are some cooling issues. If a salty, you might try just idling in a freshwater tank, maybe with a product like Salt Away.

also would find an IR sensor a good investment, if you don't have one.

[ed. Did you replace the impeller?]

 

[AJW]

still haven't tested spark? should see approx 1/2 inch sharp spark measure with an open air tester.

If this is a salt water motor, you may have a buildup in the water passages. Removing t.stats (PO) is a signal there are some cooling issues. If a salty, you might try just idling in a freshwater tank, maybe with a product like Salt Away.

also would find an IR sensor a good investment, if you don't have one.

[ed. Did you replace the impeller?]

Cfauvel - Thanks I'll check that out I'm sure there are videos on youtube to show me how to do it. I'm not looking forward to taking the flywheel off. I really think the problem is the stator but if anyone thinks there is another issue then I am all ears.

Oldboat - I did test the spark and also have run it in a freshwater tank a few times since I go it. The spark was good but that was when the engine was cooler. I am having these problems after running it a lot warmer than it gets in my driveway. I have not replaced the impeller ( I was told it was good and it pees strong,) but wouldn't it go into limp mode, or sound an alarm if the problem was overheating? I felt the head when it stalled last night and it did not feel overly hot.

 

[oldboat1]

What did the spark measure on the tester?

 

[AJW]

It was a gap tester and It sparked 20mm.

I realize now that Joe Reeves said it needed to be 7/16" but I was confused when I did the test and thought it was 7/8"

 

[cfauvel]

good idea to test the alarm.

`1 - turn key on....alarm should chirp
2 - disconnect port side temp sensor at blade connection(it will be under some rubber cover),.....alarm should sound
3 - reconnect that
4 - disconnect starboard side temp sensor at blade connection(it will be under some rubber cover),.....alarm should sound

then go ahead and test the temp sensors by removing them
1 - test continuity when cold between the middle face and the edge.....should be NONE
2 - boil them in water and retest continuity ....should have continuity ....if not replace


You can use a thermo IR reader or get yourself some specific heat reading paint that melts at known values....(Markal Thermomelt Heat Stick is what I use)....find out what temp the horn should sound and get a stick that melts just a few degrees below that.

as far as stator OHM and continuity.
1 - disconnect yellow wires from stator to distribution strip and using meter on continuity there should be NONE from either yellow wire to ground.
2 - measure OHM between the two yellow wires and jot that number down
the yellow wires are what provide 12+v required to recharge your batteries and drive GPS and other stuff

3 - disconnect connectors from stator to power pack. (not sure if you have two or one powerpack, but I suspect there are two connectors and they should be Brown wires)
4 - with some jumper wires, attach them to each pin on the stator side.
5 - test continuity from either pin to ground - there should be none
6 - test OHM from pin A to pin B , on both connectors and jot those numbers down
these are the leads for the Charge Coil....they provide 200-400V to the powerpacks...I believe in the packs are capacitors that store that energy and distribute that energy to the coils at the right time (the power packs should have another set of wires going to what ever mechanism is used to know timing...be it Timer Base or optical sensor)

BTW the timer base and optical sensor COULD go bad too and though I haven't seen it personally probably COULD affect only one cylinder....I mostly have seen it where ALL cylinders are not firing as the powerpack is not getting signal to release the energy from capacitor

look for the expected OHMs for your engine for the stator for the two coil circuits and see if you are in spec.

Even if you are, it doesn't mean the stator is good, but it is a good indication that it MIGHT be. You'll have to do the cranking voltage tests too to be sure. You'll need a DVA adapter for that. If the ohms are way off...then boom you need a stator.

 

[Joe Reeves]

It was a gap tester and It sparked 20mm.

I realize now that Joe Reeves said it needed to be 7/16" but I was confused when I did the test and thought it was 7/8"

Ha!..... And if it'll jump that, do not touch the spark plug wires when you're in the water!

 

[AJW]

Ha!..... And if it'll jump that, do not touch the spark plug wires when you're in the water!

yeah... haha. So should I retest 7/16"? or since it jumped a longer distance I assumed it was good.

I am not looking forward to these electrical tests but what has to be done has to be done. My alarm does not chirp when I turn the key to on, so maybe the whole alarm is busted.

I'm also nervous that all of these tests will probably come out good while cold in the driveway, but in order to get the temp up to what I need for the malfunction I have to be running for a while.

 

[cfauvel]

ohoh ...step 1 get that horn working....you may INDEED be overheating the engine and not know it...

`1 - turn key on....alarm should chirp
2 - disconnect port side temp sensor at blade connection(it will be under some rubber cover),.....alarm should sound
3 - reconnect that
4 - disconnect starboard side temp sensor at blade connection(it will be under some rubber cover),.....alarm should sound

forgot to state that in step 2 and 4, that you ground the connection (not the side with the temp switch)

 

[Fed]

I wouldn't bother testing the stator other than putting the spark tester on it when it failed.

I like post #17 at the moment.

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.

Everyone needs a portable tank sometime, buy one, fill it with fresh fuel & go fishing.

 

[AJW]

I can try an aux tank, but it just seems bizarre that I would have no problems with my previous engine (the exact same one) and then immediately have problems with this one. The tank is pretty new and I have a brand new water/fuel separator. I also disconnected the gas line to test the gas, and there was no water or contaminants.

My old engine didn't have the alarm when I turned the key either. It's definitely possible that it is overheating, but I don't understand why it wouldn't go into limp mode like the last engine.

 

[Fed]

Does it have a tan wire and a black/white wire coming out of the Port temperature switch?

 

[AJW]

Just want to mention that it was the power pack in case anyone in the future is dealing this with the same problem. Thanks everyone for the help!