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1995 130HP Johnson V4 (2 stroke) no ignition on port side

M

Mirco

Member
Hi guys, I'm have an ignition problem, both port cylinders are not working, not getting a spark. I changed sparkplugs and leads and also changed the coils around from port to starboard and vice versa, but the the problem remains the same: the engine works on the two starboard cylinders, and the port cylinders are dead, and the coils, spark plugs and leads are fine.
Now - I had a similar problem in March 2020, and then put in a new powerpack AND a new stator. That solved the problem for the summer, but by oktober I started getting some hickups: one out of 5 times the engine would die out on me when putting it in forward (no problem in neutral). I managed to ignore this for a couple of months by putting it into forward in one quick movement to full speed and then slowing it down, that usually would solve the problem. But since a month or so it worstened, and now runs only on the two starboard cylinders.
Does this sound - again - like a powerpack failure? The powerpack is one year old and quite expensive. Why would it blow again, after a couple of months? Is it just bad luck, or is something causing it to rapidly break down? Or could this be anything else? Your input is much appreciated.
 
Time to test stuff.------Do an ohm check on what is called the ignition charge coils.----Then the sensor coils.-----Report your numbers.
 
Ok, here's an update. I moved the powerpack a bit out of the way to check on the wires, they seemed rather worn. I disconnected and connected all connectors, there may have been a loose connection. I verified that the connections are working properly. I opened the amphenol connectors on the timer base and, according to the manual, connected an ohm-meter between the central port timer base connector (terminal "E") and alternately to all terminals on the starboard connector. The Red and Green wires measured within specs (126 ohms, should be 130 +/- 30 ohms), but both the Lightblue and Purple wires measured 15 M Ohms. What does this mean? In the book it does not say what to do next in this case. I verified that there is no grounded condition.
I put everything back together, tested all 4 sparks with a spark tester, and they ALL 4 produced a bright strong spark over 1/2 inch of distance! My messing around with the wires may have fixed something there. I connected everything back up, but no smooth engine. Starboard cylinders work fine and the block gets hot, on the port side it remains cool. I then removed the (working) starboard leads, removed the carb cover and sprayed some enginestarter in the port intakes, and - both port cylinders fired up and the engine runs on only the PORT cylinders while there is enough startfluid spray. The engine runs (roughly) on all 4 cylinders when I use the spray on the port side.
Bearing in mind the reading of the ohm meter and the rest of the story, where does this lead to? To a mechanic? I'm clueless right now. Could this be a timer thing?
 
Hi racerone, I wasn't actually :rolleyes:. It did cross my mind while I was doing the testing, but I thought that would probably not be so and I dismissed the thought. Thanks for pointing that out. It doesn't make all that much difference I think for the whole story, but it's good (very) basic knowledge.
 
Makes a BIG difference in story!!!! If you spray into PORT carbs and RPM picks up the STARBOARD side is lacking fuel.
 
After a lot of testing and cleaning wires and wire connections I came a step further. Seems all wiring is really old and squeaky. But: the spray is not necessary anymore - all cylinders are back to firing! I also remeasured all resistances in the sensor coils, they are all well within specs now. I am getting the feeling that the ignition system is actually working now. But the engine is far from smooth. It starts reasonably easily, idles reasonably well for about 5 minutes, and then starts sneezing and coughing before it shuts down. If I try to prevent it from shutting down by raising the idle lever it shuts down practically immediately. Tomorrow I'm gonna try a different tank of fuel for the h of it. I have also checked the timing according to the Joe Reeves method (also temporarily disabling quickstart) and it is exactly 14 degrees, which it should be (4 degrees less than 18).
Now I read somewhere that I should try and advance the TDC by another 2 degrees, and also adjust the lean/rich screw. According to the book, these should be 2,5 turns out, which is what it is now. What do you think? Could trying to advance the TDC by 2 degrees hurt of should I forget about that?
 
It sounds to me it’s wiring, I had a similar problem with mine and found the kill wire ( black/yellow) from stator to power pack was wore and trying to arc to ground.. motor would run smooth then start missing and backfiring.. fixing all the old wires I found solved the issue.
 
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Thanx Spence648. I may have to invest some time and money to completely change the wiring. For now, I advanced the timing 2 degrees, it did not make any difference, so I put it back to where it is supposed to be. Found something else though: due to excessive smoking and too oily plugs and carbs, I decided to take the VRO apart and found a serious tear in one of the valves, it may mean that too much oil passes through the tear into the fuel. I'll let y'all know.
 
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