1985 Johnson 140 VRO, Not charging and missing on one cylinder

[mfsb]

I have recently purchased a new to me boat. I am excited to have it and think my problems are hopefully something small. The engine is missing on one cylinder and it isn't charging the battery. I have the factory service manual for the engine and just have begun to start with the trouble shooting. I have approached these as two seperate issues.

On the cylinder that isn't firing, it the one the on the port side bottom of the V4 engine. I swapped the coil with the cylinder above, the spark plug wire as well. Using a timing light I verified that that coil is not firing, where as all the others are fine. I have ordered a power pack that should be here in a few days. I hope that I have correctly Identified the part that needs the replacement to fix this. I am posting about this problem hoping to get some feedback if I am going in the right direction.

On the not charging I have checked the resistance on the coil plug to verify that none of the leads have grounded out, and they appear to be fine, no ground. I have not ordered a rectifier yet because I am still not sure which part to order.

Also, with it not firing on one cylinder could this all be caused by the stator? I have a couple days and can send the power pack back for a refund, any ideas would be very helpful.

 

[nymack66]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

Power pack is what fires the plugs, stator can be tested also, a simple observation without having to remove the flywheel is use a flashlight and peek up under if you see melting,sticky, Carmel looking stuff you may have a melted stator, if not you will have to conduct the rocket science PIA testing describe in the manual, depends on if you enjoy repairing or Boating replace the pack, if not pull the flywheel and replace stator and trigger and be done with it. I am believer in never messing around testing PACK,STATOR,TRIGGER if in doubt replace. Just my 2 cents.

 

[emdsapmgr]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

You are correct, two separate problems. If your engine has power tilt/trim, it has the more sophisticated combination rectifier/regulator. (and more expensive.) Usually when the engine quits charging the battery, it is this device which is looked at first. Usually when it goes bad, the tach also acts up. You can test for a no spark condition by swapping the two power packs. If the no fire problem moves to the other head after the swap, then likely the pack is bad.

 

[mfsb]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

I replaced the power pack, didn't fix my problem. I have also looked at the coils the best I could under the flywheel, no obvious damage. I do have a little corrosion. I checked the wires, not breaks or shorts, I will pull the flywheel and replace the stator and trigger assembly in a couple weeks when the parts kitty can fund it. I will update when I do.

 

[emdsapmgr]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

Instead of just replacing, you can perform tests on the stator and timer base. Check out this website: cdielectronics.com They have some good troubleshooting information and test specs on various OMC ignition systems. I like the voltage tests, since they are measured when the engine is cranking. They require a special "peak reading" voltmeter.

 

[mfsb]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

My thoughts on replacing both is that I have narrowed it down to the trigger by replacing the Power Pack with no effect. So while I am in there I would replace both at the same time, since I will have the flywheel off. And since I have a 50/50 chance of fixing the charging issue with the replacement it fits both needs. I also don't have a peek reading multi-meter, I have a data hold version but not sure that will provide the appropriate readings. I will give it a shot, I don't like trying to take measurements right next to the spinning teeth of the flywheel.

 

[mfsb]

Re: 1985 Johnson 140 VRO, Not charging and missing on one cylinder

I just replaced the trigger coil under the flywheel. The engine is now firing on all cylinders and running much better. Not perfect yet, but can get be better. I think part of it maybe under charged batteries. I am going to figure that out first, then repost how charging went.