JOHNSON 115 HP MISSING ON ONE CYLINDER

[dngbt5]

What I have: Rebuilt 1983 Johnson 115 hp V4. I did not rebuild it and did have it running great for a short while then a spark plug wire failed and was arcing to the motor. Not sure if this could have done damage to a certain electrical part?

My Issue: Lower port side cylinder is missing. I have used my timing gun to determine the RPM’s on the problem cylinder are about half of the other 3 cylinders. I have also looked into the light and noticed the dark spots/misses when testing that cylinder.

Compression is 120 on all four cylinders

What I have done:

1. I have done a spark gap test. All four jump a 7/16 gap however I noticed the problem cylinder was missing.
2. I have checked all electrical components with a multi meter. All OHM and Volt readings were in spec.
3. I have disconnected the rectifier = no difference
4. I have disconnected the regulator = no difference
5. I have swapped coils between all cylinders and the problem does not move.
6. I have swapped power packs and with no difference.
7. I have checked and replaced spark plugs. The problem cylinder shows signs of fuel getting to the cylinder but not firing. I am guessing it is missing and firing at the wrong time.
8. I have also replaced the needles and seats in the carbs and set the floats to level.
9. I have replaced water jacket gaskets and head gaskets.
10. I have checked all grounds on power packs, coils, etc. Maybe I am missing something?
11. Battery is fully charged
12. I have done the plug pull test and the starboard side seems stronger than the port (big difference in motor, almost dies). When I pull the top port side it does affect the motor and a fairly loud ticking occurs. When I pull the lower port side there is no affect and sometimes I get shocked.
13. I have checked for dripping/meltdown under the flywheel and there is none.

Could there be a magnet loose under the fly wheel causing this? \
Could it be a bad trigger, that actually test good with the multi meter?
Bad Stator that tests good?
Is there a ground somewhere I could be missing?

Thank you all in advance for your responses and knowledge.

 

[CDI Tech]

When you say "you moved the coils" does this mean you physically removed them and remounted them or did you just swap the primary leads? Two totally different things is why I ask? If you just swap the primaries and you actually have a bad coil, the spark will not move. If you removed them and remounted, then the spark should move like you are thinking. If this is so, install a spark board and swap the green and blue wires on this pack. If the spark moves, you have a timer base issue.

 

[dngbt5]

I have moved and remounted them. I have tried switching the wires (had to cut and reconnect due to going into double plug)they are both orange coming from the power pack and I tried leaving the wires. When I just move the packs but don't swap the wires the whole motor runs very rough and at a lower rpm. When you say swap the blue and green. Does that mean between the power pack and the plug that connects to the timer base?

 

[CDI Tech]

Yes, i'm talking on the timer base side. DO NOT run the engine during this test. It will run awful and/or will not start because it will be firing out of sequence. If you do not have a spark tester use the existing plugs but ground the body to the engine first. If your spark moves, The timer is the issue. Let me know if this helps. :joyous:

 

[emdsapmgr]

You have not mentioned testing the stator or timer base. I'd probably start with testing the timer base. You can find reliable ignition testing info at this website: cdielectronics.com Specifically, they have condemning voltage outputs at normal cranking rpm's. You will need a special "peak-reading" voltmeter to properly test for these voltages. The normal output voltages for a timer base could be a minimum of around 0.3 volts. The stator perhaps a minimum of 150 volts. Check for the output voltages for your year engine. The rectifier/regulator are on the charging side of the stator and have nothing to do with ignition firing.