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Challenging issue with crank but not start

A

AMT

New member
I have an Evinrude 90 HP outboard 2 stroke 4 cylinder year 1995 on a 17 ft boat. I noticed that it had trouble restarting when stopped for fishing and trying to retstart. It seems to turn fine and crank but did not start. I did after few tries. This happened a few times. Started always, especially by keeping it running a 30 seconds or so on the starter motor.

Now the issue is that it turns but does not start. I even replaced a new battery and starter, sparkplugs ( it has spark and jumps 3/4 cm). Checked for fuel issues and cleaned up the carborateur. The spark plugs seem to get the oil fuel mixture. It does seem to cough and has smoke from the exhaust.

Also compression seems to be low around 60 in each cylinder with hand crank. (Starter motor is being replaced). The compression is low but should start right? May not have a lot of power but engine should start. But it is not. Which is the challenge. Why?

What could be wrong? Powerpack?



Thanks for your expert help.

AMT
 
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I have a 1990 Johnson 70 VRO with the same problem. Just refuses to start. I am pushing the key into the key assembly when I turn it over, the plugs smell like they are getting fuel and even with starting fluid it refuses to kick. So if you get an answer, I will look forward to finding out what gives!
 
With compression at 60 PSI you need to test with another gauge.-----Or you have serious internal problems and motor will never start / run properly.
 
Engage an electrical starter for NO MORE than 20 seconds, then give it some time to cool off. Exceeding that time causes the starter to overheat which will, in time, cause the solder portion of the armature (Commutator) to melt. In any case, exceeding 20 seconds will very likely damage the starter.

A compression reading of 60 psi in "all" cylinders is quite unlikely and is probably due to being slowly pulled over by hand via a pull cord (as stated). Compression naturally varies with the speed of which the engine turns/cranks over.

The engine must crank over at least 300 rpm in order for the stator to energize the powerpack!

Closely observe the stator under the flywheel, and look for a sticky looking substance to be dripping out of it, dripping down on the timer base and powerhead area. If this scenario exists... replace the stator! That situation causes a AC voltage drop from the stator to the powerpack's capacitor which results in weak, erratic, and eventually no ignition/spark.

Let us know what you find.
 
:)
joereeves said:
Engage an electrical starter for NO MORE than 20 seconds, then give it some time to cool off. Exceeding that time causes the starter to overheat which will, in time, cause the solder portion of the armature (Commutator) to melt. In any case, exceeding 20 seconds will very likely damage the starter.

A compression reading of 60 psi in "all" cylinders is quite unlikely and is probably due to being slowly pulled over by hand via a pull cord (as stated). Compression naturally varies with the speed of which the engine turns/cranks over.

The engine must crank over at least 300 rpm in order for the stator to energize the powerpack!

Closely observe the stator under the flywheel, and look for a sticky looking substance to be dripping out of it, dripping down on the timer base and powerhead area. If this scenario exists... replace the stator! That situation causes a AC voltage drop from the stator to the powerpack's capacitor which results in weak, erratic, and eventually no ignition/spark.

Let us know what you find.
Click to expand...

Thanks Joereeves.
I got a new starter and hooked it up. As soon as I was trying to crank it up it seems that the new starter also started to give trouble like staying locked up with the Flywheel even after I off the power switch key. If it becomes disengaged, it seems to shreik internally, and seems to be just rotating internally and not engaging the flywheel.

I had imagined that with a new starter, I could test the compression at least if it does not start. Strange that the new starter will also not work well.

I will look for the fluid under the stator.

Thanks for your continued help.
 
Is that new starter a brand new starter of just new to you? It should not shriek!

Shrieking of the starter is normally/usually caused by dry bushing that the armature rotates within.

The bendix gear will normally stay engaged in the flywheel teeth... unless the engine fires. It is the sudden increase of rpms that causes the flywheel to kick the gear out of the ring gears teeth.

When the gear is fully engaged upon the flywheels teeth, check to see that it has a sight bit of play and is not jammed in the teeth.

If that starter is brand new and is not cranking the engine over at a fast rpm... either the starter is faulty... OR... there is a bad connection in the cables/wiring somewhere that is causing a voltage drop.<-- If this is the case, clean all the cable terminal ends and the components they attach to, then tighten them securely.
 
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Thanks, JoeReeves.

It is a brand new starter. It sometimes engages and sometimes shreiks.
The stator area seems to be clean. I also have new power pack that I will install and check if there is any change in the way it operates or at least shows strong combustion blast at at least one or more of the strokes and post the results to the forum.

If this does not fix the issue the only section of the ignition is the stator. I may change that and see what happens. Hopefully it should fix the issue.

Thanks so much for continued interest in this intriguing problem.
 
Thanks Joereeves, you keep on sharing your knowledge on this issue. Such a new member like me, it is a great help to have this kind of contribution. This will be my future reference with troubles ( but hopefully nothing ). See you around.
 
AMT said:
Thanks, JoeReeves.

It is a brand new starter. It sometimes engages and sometimes shreiks.
The stator area seems to be clean. I also have new power pack that I will install and check if there is any change in the way it operates or at least shows strong combustion blast at at least one or more of the strokes and post the results to the forum.

If this does not fix the issue the only section of the ignition is the stator. I may change that and see what happens. Hopefully it should fix the issue.

Thanks so much for continued interest in this intriguing problem.
Click to expand...

OK, I got a new Starter and installed it. Checked the compression and on all cylinders it is about 100. So it seems that compression, although lower it should be ok for running, if not at max power.

Changed the power pack and tried starting using the regular starter key. It turns and started fine.:eek: . Tried to stop and start several times and it started right away. I could throttle fine.

Now new challenge develops:
The motor started misfiring every 1 minute. :mad: but it was not stalling. So I planned to take it to river to see how it performs.
Now at the river, when immersed it in water, it refused to start easily. After many tries, and stalls, it started rough with intermittent misfires. But as soon as I put it in gear or given a load, it dies. Now it does not start under load.
I am going to check the spark, coil again as I suspect the spark plug wire got stuck in the cover hook when opening it and got loose. I pressed it against the coil so it can stay connected. But that may be the issue related to misfire on that cylinder.

I will change the spark plug wires and continue to investigate why the engine stalls under load. Will need to check the spark and if that is ok, only thing remaining may be fuel pump. Even though enough fuel is coming in while idling or even full throttle under no load, Is it possible that the fuel is not sufficient under load conditions.

Is there any other issue that I should investigate related to it dying as soon as the motor is immersed in water and subjected to load?
 
AMT said:
OK, I got a new Starter and installed it. Checked the compression and on all cylinders it is about 100. So it seems that compression, although lower it should be ok for running, if not at max power.

Changed the power pack and tried starting using the regular starter key. It turns and started fine.:eek: . Tried to stop and start several times and it started right away. I could throttle fine.

Now new challenge develops:
The motor started misfiring every 1 minute. :mad: but it was not stalling. So I planned to take it to river to see how it performs.
Now at the river, when immersed it in water, it refused to start easily. After many tries, and stalls, it started rough with intermittent misfires. But as soon as I put it in gear or given a load, it dies. Now it does not start under load.
I am going to check the spark, coil again as I suspect the spark plug wire got stuck in the cover hook when opening it and got loose. I pressed it against the coil so it can stay connected. But that may be the issue related to misfire on that cylinder.

I will change the spark plug wires and continue to investigate why the engine stalls under load. Will need to check the spark and if that is ok, only thing remaining may be fuel pump. Even though enough fuel is coming in while idling or even full throttle under no load, Is it possible that the fuel is not sufficient under load conditions.

Is there any other issue that I should investigate related to it dying as soon as the motor is immersed in water and subjected to load?
Click to expand...

Got new spark plug wires and replaced the old ones. Now I am trying to start it and it refuses to start even with the muffs. Only cranks. I checked the spark and it is coming fine. Even sprayed some gas mix in the carborator and it still does not start only cranks. I removed the output from the pump to see if it squirts gas when I crank the motor. It does squirt gas. I have not connected a pressure gauge to see how much pressure it is generating. Hoping that the squirt may be at least sufficient to get the engine started if that were the issue.

I will continue to investigate the fuel pump and stator, the only thing remaining now.
 
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racerone said:
Checked the flywheel key ?
Click to expand...

Good point a lose freely or inconsistent rotating flywheel that is not snug with the crank may mess with the timing and motor won't start. But I have not yet tested the flywheel key. As have not yet removed the flywheel.

The flywheel though does not seem to be lose or have any play while rotating it which seem to indicate that the key is snugly fit. Also, the flywheel does not seem to be rotating without the crankshaft movement.
 
Got it started after cleaning up all terminals associated with the power pack, spark plug and coils. It is now running fine. Thanks for all the help and investigation. It was fun opening up each system fuel, starter, ignition etc. multiple times. When there are inconsistent and irregularly irregular issues, especially with electrical ignition system, it may be a good first idea to clean up all contacts and check wires for continuity. I saw lots of resistance develop in the contacts due to rusting that may cumulatively cause inconsistent firing, synchronization and rough start.

As an engineer myself, it was a challenge worth it. It was first time I opened up so much of the outboard and reassembled it back several times. But now I can go into water more confidently and know much more on what is happening if there are issues. :eek:.
 
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Mingku said:
I have a 1990 Johnson 70 VRO with the same problem. Just refuses to start. I am pushing the key into the key assembly when I turn it over, the plugs smell like they are getting fuel and even with starting fluid it refuses to kick. So if you get an answer, I will look forward to finding out what gives!
Click to expand...

Check my final fix. It fixed my problems of hard start if at all it would. and inconsistent working of the motor.
 
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