1997 Johnson J15REUC 15hp - top cylinder not firing

[Ivco]

I want to start with the fact that I am new to outboard engines, but I have tremendous desire to learn how to troubleshoot and fix them! I friend of mine was kind enough to let me work and learn on his engine for which I am deeply grateful. Thanks, Jon!

Engine: 1997 Johnson J15REUC 15hp, 2 stroke engine, manual start

Original problem: The top cylinder does not fire

Steps that I have taken to troubleshoot this issue:

1. Supplied water to the engine, connected the gas tank, primed until the primer was firm, pulled the cord

Result: 1. The engine started but when I disconnected the spark lead from the top cylinder the sound of the engine did not change. 2. With the throttle almost closed the engine was not idling well and was turning off.
Conclusion: original problem confirmed, need to eliminate fuel issues
Mental health: I am very excited; never worked on an outboard engine before! Hungry to learn!​

2. Removed and thoroughly cleaned the carburetor to eliminate any fuel problems

Result: no change, with low RPMs the engine was turning off
Conclusion: probably the idle was not good because only one cylinder was working, weak argument but decided to focus on and fix the electrical issue and then assess the idle again​

3. Tested the kill switch with multimeter to make sure it is functioning properly

Result: tests showed kill switch is good also I had spark on the bottom cylinder
Conclusion: kill switch is good​

4. Pulled out the spark plug from the top cylinder, pushed it against ground, pulled the start cord

Result: no spark
Conclusion: the cylinder does not fire because of electrical issues​

5. Swapped the orange wires on the primary coils which are coming from the power pack

Result: again, no spark on the top cylinder
Conclusion: possibly bad ignition coil​

6. Removed the coil pack from the engine to make sure I am not measuring any parallel resistance and measured the resistance of the primary and the secondary coils using multimeter. For the primary coils I measured between the ground plate of the pack and the connector for the wire from the power pack, for the secondary coils I measured between the ground plate of the pack and the connector for the spark plug lead

Result: Measurements in spec
Top cylinder primary coil: 0.5 Ohm
Top cylinder secondary coil: 307 Ohm
Bottom cylinder primary coil: 0.5 Ohm
Bottom cylinder secondary coil: 311 Ohm
Conclusion: faulty coil pack, not very convincing because the resistance measured in spec​

7. Bought a new coil pack, before I put it in the engine, I measured the resistance on the primary and secondary coils

Result: in spec, measured very close to the old coil pack
Conclusion: looks good, time to install and test the new coil pack​

8. Installed the new coil pack into the engine, I made sure the ground was solid and tested continuity with the multimeter, pulled the cord to check for spark

Result: since I could not see while cranking the engine, I asked my wife to check for spark and she said that there was a spark
Conclusion: Good to start the engine!​

9. Put the spark plug into the top cylinder, connected the spark plug lead, and attempted to start the engine

Result: It took some cranking, but the engine started, again only the bottom cylinder was working
Conclusion: need to inspect the power pack, weak argument because swapping the power pack wires on the coils did not change anything and I was still getting spark on the bottom cylinder​

10. Attempted to measure the voltage on the orange wires from the power pack, while everything was connected back to normal I connected the DVA adapter to the orange wire from the power pack and the other lead to ground, cranked up the engine

Result: measured just a few volts, same measurement on the other orange wire from the power pack
Conclusion: this is not the right way to measure the output from the power pack, read some Johnson service manuals, watched YouTube, read a lot on Internet, everything pointed that I measured the proper way​

11. Disconnected the orange wires coming from the power pack and connected a load resistor (10ohm, 10watt) in series (one end to the orange wire the other to ground), connected the DVA adapter to both sides of the load resistor to measure the voltage on it, cranked up the engine

Result: very low voltage reading, do not remember the right value
Conclusion: I do not know how to measure the output of the power pack​

12. Decided to measure the outputs of the secondary coils, removed the load resistor from the previous test and connected all wires, connected the DVA adapter to the spark plug lead and ground (the spark plug lead was connected to the coil and spark plug as it should)

Result: the voltages were not high enough to produce a spark, but I was getting a spark on the bottom cylinder
Top cylinder secondary coil: 15V
Bottom cylinder secondary coil: 22V
Conclusion: I do not know how to measure the voltage on the secondary coil
Mental health: I think I am going crazy​

13. Disconnected the Amphenol connector between the stator and the power pack and measured resistance at rest and voltage while cranking. Confirmed neither the charging coil nor the trigger coil are connected to ground

Result: measurements in spec
Brown/brown-yellow (charging coil): 868 Ohm, 146V
Black/black-white (trigger coil): 41 Ohm, 5V
Conclusion: power pack not good, weak argument because it seemed I did not know how to measure the output of the power pack​

14. Bought and installed a new power pack

Result: no change, no spark on the top cylinder
Conclusion: I missed to check the resistance of the spark plug leads
Mental health: I am definitely going crazy​

15. Measured the resistance of the spark plug leads

Result: measured 230 Ohm, expected close to 0 according to a free Johnson manual that I found on Internet (http://boatinfo.no/lib/evinrude/manuals/1990-2001johnsonevinrude.html#/220)
Conclusion: Called Johnson/B.R.R then Gary’s Marine Engine, turned out that resistance should be close to 0 but 230 Ohm is not a problem. Decided not to change the spark plug leads.​

16. Since I had already lost my sanity, I decided that I cannot trust anything, and I must check everything ignoring the fact that this engine was working like a Swiss watch before. Went to Marine Engine to check the recommended spark plugs for this engine.

Result: recommended QL82C or equivalent, NGK BR7HS-10 installed in the engine
Conclusion: wrong spark plugs​

17. Replaced the spark plugs

Result: no change, same problem
Conclusion: the only thing left was the stator. “The problem must be there!” Weak argument because both the trigger and charging coils measured in spec
Mental health: I am worried that after all this I still cannot pinpoint the problem​

18. Bought a used stator, part number the same as the recommended on Marine Engine. installed it on the engine, fits nicely under the fly wheel. Before connecting the power pack, I measured the resistance and voltage of the coils

Result: measurements in spec
Conclusion: OK to connect the power pack and test​

19. Tested for spark with the new stator

Result: no change, same problem
Conclusion: I will use the bottom (working) coils of both coil packs and see if I can get two good sparks. Frankenstein "It's Alive" like Joh said
Mental health: I cannot sleep any more​

20. Finally, with the Frankenstein setup I had two good sparks! Yes, I connected the ground leads of both coil packs to the engine block! Time to test how the engine runs!

Result: The engine does not start, not even the bottom cylinder
Conclusion: possible fuel problem, weak argument because the fuel supply was working before​

21. Removed the spark plug from the cylinder and put some fuel-mix into the cylinder, expected the engine to fire for a few seconds

Result: the engine did not start, smelled like fuel around the prop, the fuel did not burn out and was pushed out of the exhaust?!?
Conclusion: N/A
Mental health: no words to describe it​

22. Removed the spark plugs to check for sparks again

Result: sparks on both, Unrelated to this test but I noticed a fuel leak from the fuel pump. Will order parts and fix it.
Conclusion: I need help!​

Questions:

1. Assuming that you had the patience to read all this, did I make any logical mistakes?
2. What is the right way to measure the output of the power pack before and after the ignition coils?
3. Do you have any ideas what the problem may be?

Any help is much appreciated!

 

[Ivco]

"Engines need three things to start: fuel, compression and a spark". I have confirmed I have sparks! I put fuel mix into the cylinder to eliminate fuel delivery issues! The only thing that is left is compression!

I measured the compression of my engine
Result: 50psi on both cylinders
Conclusion: not enough compression to start the engine. Since this engine was working before and because the compression is exact same on both cylinders, I suspect the head gasket. I'll remove the head and inspect the head gasket. Even if the head gasket is not the problem I need to look at the cylinders anyways so removing the head of the engine will not be wasted effort.

I also spent some time chasing the fuel leak. There is a screw that presses a plastic cap with a couple of O-rings to the body of the fuel pump. This screw is threaded into a metal insert at the center of the pump. Somehow the front several threads of the metal insert were stripped, and the screw was not catching properly leaving it lose, hence the fuel leak. I bought a little longer stainless-steel screw which catches the back threads of the metal insert. I do not think the new screw is touching anything at the back but we will see. Now my primer bulb gets firm after squeezing it a few times and there is no fuel leak!
The alternative was to buy a whole new fuel pump but we decided not to do this right now.

We also ordered a new coil pack (this is the second one :-() with spark plug leads which is supposed to arrive today. Even if it does, I cannot test it immediately because the compression problem needs to be addressed first!

 

[merkdawg0084]

First of all, slow down. You’re making it way too complicated. Always check compression on a motor first, Then check spark on each cylinder. Then fuel. First thing. 50 psi is horrible, definitely check head gasket, Then go back and check compression. There is a great website called Leeroy’s Ramblings. Check it out it’s pretty easy to navigate. Good luck

 

[Crosbyman]

info ...

http://www.leeroysramblings.com/OMC_info/OMCinfo.htm

btw also check your compression meter.... try another one. I have some 9.5hp turtles that run fine at 65 psi

fuel will explode in a can of coke .... sounds like your engine wont even sputter a bit.

btw I suspect your original coils are fine...being modrn ones. just mho
does your sparks jump 3/8 7/16 inches...yes or no??

a longer screw in the fuel cap may have punctured a diaphragm :-(

how did you "thoroughly " clean the carb...?
http://www.leeroysramblings.com/Johnson_9.9_carb-fuel_pump.htm

 

[Ivco]

Thank you for your replies, merkdawg0084 and Crosbyman!

Wow! The OMCinfo on Leeroy’s Ramblings is awesome! This is great info!

Answering Crosbyman:
I have two compression testers. I measured with both. See below.
I do not have a spark plug tester with adjustable gap – I should buy one. I have the one with a light bulb.
The new screw that I put on the fuel pump was a few millimeters longer than the original screw. According to me it is just enough to catch onto the good threads without sticking out. I understand that there is a risk of it being too long and damaging the diaphragm.
I removed the carb off of the engine, completely disassembled it and separated the rubber parts, used compressed air to blow any debris, used copper wire to run through the narrow passages and holes, used carb cleaner on the metal parts, used Q-tips to reach some difficult places. I inspected all gaskets and rubber pieces for damage but since the carb was rebuilt recently everything seemed to be in good shape and I did not see a need to use a new carb rebuild kit. Then I completely dried out all the pieces with compressed air and assembled it.

.. so here is the continuation of the saga:
With both spark plugs removed and full throttle I measured the compression of both cylinders. Here are the initial measurements (as I mentioned above, I have two compression testers):

Compression tester #1: 50psi on both cylinders
Compression tester #2: 60psi on both cylinders​

I sprayed WD40 in both cylinders, left it overnight and then a few more times on the next day. After that I measured the compression again using compression tester #2:

Compression tester #2 attempt #1: 70psi on both cylinders
Compression tester #2 attempt #2: 65psi on both cylinders
​

I was about to pull the engine head off, but… again, this engine was working just fine before so, I decided to test with the new coil pack before I open the engine.
I took leads that came with the new coil pack and I measured the resistance. Both measured <1 Ohm which is normal and in spec. I put the new coil pack and leads into the engine and I got two really nice and bright sparks. Just to check one again I tested one of the old coil packs and I got only one spark which confirmed the theory that it was damaged. I put back the engine with the new coil pack and the new spark plug leads, connected the fuel tank, choke on – one pull, choke off – one pull and THE ENGINE STARTED JUST FINE! With the throttle set to low the engine purrs like a kitten!

Learnings:
My friend Jon and I were trying to summarize the problem, the solution, and our learnings. After all this we had two new spark plugs (of the correct/recommended type), spark plug leads with low resistance, a new coil pack and a fix for the fuel pump. The most logical explanation is that because of the wrong spark plugs and leads the original coil was damaged, then I put the second (brand new) coil and I tested it with the same spark plugs and leads and I damaged it, too. It is still strange though because the resistance of all three coil packs (primary and secondary coil) measure in spec. I read that coils can measure in spec with a multimeter but when a high voltage is applied, they can still malfunction. I wish I knew how to determine if a coil is bad without putting it into the engine. The issue with the fuel pump was a problem but orthogonal. I guess the thread was stripped since the beginning, but it was barely put together not to leak. In the process of working on the engine I must have wobbled it and because of that it started leaking.

I would really appreciate it if someone explains how to test the voltage on the primary and secondary ignition coils when cranking the engine. Steps #11 and #12 of my original post explain how I tried to do that.

 

[racerone]

Throw away your tester with the light bulb.----Heave it over the fence as far as you can !!!

 

[flyingscott]

How are you testing compression? Are you pulling the motor over until the gauge stops moving? A minimum of 5 pulls.

 

[Crosbyman]

I doubt the spark plugs would have caused coil failures unless they were open..

firing HV coils with no ground to reach to consume the energy kind of forces the high voltage pulse to search for somewhere to go to expend all that energy .

any weakness in insulation inside the coil will be a target and end up in a new path vs the plug .

poor imsulation , cracking humidity is what killed the old coils :-(

 

[Ivco]

@racerone
You are right! I did some research and it seems like the Oppama PET-4000 is the way to go.

@flyingscott
I made sure that the gauge was zeroed before I started. With both spark plugs removed and full throttle I installed the compression gauge on the first cylinder and pulled the start cord a few times until the gauge stopped moving.

@Crosbyman
Thanks for the explanation!

I noticed that the engine shakes a little when idling with the throttle set to low. I will try to adjust the adjusting screws on the carb to make it idle better.

 

[Ivco]

I asked similar question in the thread that I started titled "1997 Johnson J15REUC 15hp - top cylinder not firing". I concluded that I do not know the right method to measure neither the output of the power pack(on the primary coil) nor the voltage on the secondary coil. No one has answered the below question, yet:
"I would really appreciate it if someone explains how to test the voltage on the primary and secondary ignition coils when cranking the engine. Steps #11 and #12 of my original post explain how I tried to do that."

This is what I've tried and wrote in my thread:
11. Disconnected the orange wires coming from the power pack and connected a load resistor (10ohm, 10watt) in series (one end to the orange wire the other to ground), connected the DVA adapter to both sides of the load resistor to measure the voltage on it, cranked up the engine

Result: very low voltage reading, do not remember the right value
Conclusion: I do not know how to measure the output of the power pack​

12. Decided to measure the outputs of the secondary coils, removed the load resistor from the previous test and connected all wires, connected the DVA adapter to the spark plug lead and ground (the spark plug lead was connected to the coil and spark plug as it should)

Result: the voltages were not high enough to produce a spark, but I was getting a spark on the bottom cylinder
Top cylinder secondary coil: 15V
Bottom cylinder secondary coil: 22V
Conclusion: I do not know how to measure the voltage on the secondary coil
Mental health: I think I am going crazy​

13. Disconnected the Amphenol connector between the stator and the power pack and measured resistance at rest and voltage while cranking. Confirmed neither the charging coil nor the trigger coil are connected to ground

Result: measurements in spec
Brown/brown-yellow (charging coil): 868 Ohm, 146V
Black/black-white (trigger coil): 41 Ohm, 5V
Conclusion: power pack not good, weak argument because it seemed I did not know how to measure the output of the power pack​

 

[Ivco]

Please ignore the last post. This is a post that I had on another thread and in my opinion was incorrectly moved here by one of the moderators.