DT200 1998 3 left cylinder not firing ( when motor not covered )

[jagrav]

Hello, I have a DT200 from 1998, these motors are amazing - never had any problems exempt this. Love Suzuki! And I thank you in advance for reading my lengthy post!!!

The motor does not fire the 3 left cylinders. Now here is the weird part - if I cover it up nicely as to protect it from cold/rain/weather, it regularly works great. However if left without a cover ( just the engine cover of course) and part of my boat cover that goes over the engine.. the problem appears and it needs to be turned on and ran with just 3 cylinders (for up to an hour sometimes) and THEN all 6 start to fire.


Today:
I went out to check it out, on the first crank - 3 right cylinders, so I started to check sparks - no sparks on left side, so I came in and read everything I could find about this sort of issue...

These are my findings -

1, the "low oil sensor" may be interrupting

- However if this was the case I'd think all 6 would stop firing

2, the strator ( coils - high or low ) could be damaged

- Does not seem likely to me since the motor idles beautifully once all 6 cylinders start to fire. ( and accelerates and reaches high RPM nicely also )

3, neutral switch

- Again, if this would be the case.. I'd think none would fire.

4, CDI ( which I read cannot be tested)


Later went back out.. cranked it.. and just as I was going to start my diagnosing, they all started firing ( I had it covered since 2 nights ago when i cranked it and the left 3 cylinders would not kick in )

First question -So the issue will have to wait until tomorrow when and if it presents itself again, I was not able to diagnose CDI by switching the coils from the right cylinders to the left. However, once the problem returns, can i just put the coils from the right cylinders in order on the left bank, without causing harm to my motor? I mean switching the spark coils 1,3,5 with 2,4,6 .. will it cause any timing issues?

Second question - Which of these problems seem more likely to be the culprit? Taking into account ( highly ) that it happens when the engine is not protected from the environment?

Third - Could anything else be going on that I have not mentioned here?


Lastly... Thanks So Very much!

[Solarman]

dt200, 98, intermittent firing on port side

Ok, I don't have your wiring diagram in front of me, but it seems like maybe humidity, moisture might be the problem. You should look at wire schematics for temp, oil, pressure sensors, or any other device (kill switch, limit switches?) That might be wired into one bank (port) instead of the system?

If low oil sensor its wired to affect one side, maybe?

Your stator appears to work for one side, therefore it is working for both. Not the problem.

The neutral switch prevents starter from even starting the motor. It should turn off the solenoid power. However, my brothers Johnson motor, did have a neutral switch on the motor (not control switch), that cut fire/spark to his 3 port cylinders? Have to check wire schematics for such things?

The cdi you're referring to is a Condenser Discharge Ignition module. The same cdi works for all cylinders, why for only half? It receives a charge from the stator and fires for every signal from the single ignition timing coil, with respect to the gear counting coil and tps. Which also seem to be working, as starboard side seems fine, and in time.

I might consider your coils for one side, but all three doing the same thing? Not a good choice if playing the odds.

I would think your odds are in favor of moisture/ humidity affecting ground connections, wire plug connectors/ connections, and if moisture is the culprit, I might look for multiple wire connectors that connect the port coils to the electronics/ cdi /icu/ ecm?

The grounds are still a culprit, but I think moisture is affecting the signal coming to the port bank by shorting to ground (inside the same connector) the signal(s) being sent. Seems to dry out after running for some time.

Check it out, let us know what you find. Good luck.

[jagrav]

Thanks so much for the quick reply, I am going out right now and seeing if the problem persists, if it does I will check out some connections and maybe spray some electronics cleaner where ever I can. I do not have the book yet, but I think I will be ordering it soon, so I can see all about the sensors and kill switches and if it is possible that they are affecting only one side of the motor. Thanks again, I will let you know how it goes.

[jagrav]

Went back out. It was the Low Oil Sensor . Thank you so much.. next up is checking the batteries not charging. Bought a book for my motor online but it is horrible quality... and i will NOT pay 90$ for a book from the website... so when I get the schematics I should be able to check if its sending current back or not..

Thanks for your help!

[Solarman]

dt200, 98, no fire port side

So you found out the low oil sensor did shut down the spark to the left side of the motor? Did you replace the sensor, our was it a bad connection?
Post what you found. Thnx.

[jagrav]

I believed it was the low oil sensor a while ago, and the motor had been working good since I disconnected the ground from the oil sensor; however it seems that it was not the issue at all, we were cruising the other day and all of a sudden the boat lost power, after a quick check we realized that there was no spark on the starboard side of the engine ( none of the 3 cylinders ). I have checked the IGNITION COILS by switching all three of the working ones to the other side - nothing changed. We checked the resistance on the 3 PULSAR COILS and it shows that they are also up to spec. We have checked cables and cleaned most connections. We cleaned out the OVERHEAT SENSORS. I cannot think of anything else to try. Why would all 3 cylinders on one side stop? I am out of ideas! Please help!

Thanks!!!

[Solarman]

If you have the wiring schematic now, you can locate the neutral switch on the motor, and check it (bypass it to see if causing your problem, also check temp sensors.

If still having problems with charging system, it might be related to your problem, but wouldn't set off the alarm.

Good luck, post back when able to let us know how it's going.

[jagrav]

I'm on the boat all day today.

I do have the diagrams, but the neutral switch that it shows is not on the motor itself, it's right after the ignition switch . I think I may know what you are talking about, i saw something about following the shift linkage and finding the one in the motor , i will have a look now and see if i find it.I have also looked into the timing of the motor to see if that could be the issue, but the DT200 is not user adjustable as per the workshop manual ( it is all taken care off in the CDI unit ) .I wanted to upload photos but I can't because the size limit .

[Solarman]

The neutral switch on the shift linkage at the motor is the one I'm talking about, not the one in the throttle controls.

Check the voltages from the stator, and rectifier by the manual.

Good luck. Post back when able to let us know.