Loosing spark on one cylinder after some running

[matthieu]

No matter whether I go full throttle or low speed, after some time I lose spark on the bottom cylinder. Turning off the motor and waiting doesn't do anything, unless I wait a very long time, but sometimes it just starts working again on its own while running. This problem is seemingly random, so it's not easy to reproduce to test and I have to do most of it on the water. I tried swapping the coils to no avail. Also replaced the power pack, no change. I unfortunately do not have a DVA, but there isn't much else that can fail. Some people say problems at high speed are usually stator. I have one from another motor that I could use to replace but have never pulled the flywheel and don't know how hard it is to do so and replace the stator. Are there any adjustements to do after you replace the stators/flywheel? Could the trigger be the problem? Ground wire maybe bad?

Thanks guys

Evinrude E70TLEOR 95' 3 cylinders 70HP

 

[emdsapmgr]

Weak ignition components tend to fail once the engine heats up to normal operating temps-and this sounds like the probably cause. The coils are generally pretty reliable. From a pure statistical standpoint, the power pack is the ignition part that is most likely to fail. You've already replaced it. That leaves two items, the stator and the timer base. Both expensive and can be tested with some electrical know-how. It will pay you to do some troubleshooting. You will find some great troubleshooting info for these two parts at cdielectronics.com. Both can be qualified by testing with a peak-reading voltmeter when cranking the engine. You can probably rent that voltmeter at most automotive parts stores. Compare your cranking voltage outputs with the condemning voltages from the website's guide.

 

[Bosunsmate]

You can get a $8 multimeter and test the stator out on the water when it fails and even on land it might show up your problem. Just check the resistance values. In my experiences they show up as being out of spec if the stator is bad so you dont need a peak voltage DVA reader. You can also read the voltage output when the motors working ok and then again when its bad, if its suddenly dropped then the stators the problem, you dont need a dva for that as you are just comparing apples with apples.

You can also check the timing base as well out on the water and on land the same as above, Also check that there is no contact between the timing or stator wires to an engine ground. Use the multimeter to check there is infinite resistance between all the wire connectors coming from the stator/timing base and ground (ie no connection). Sometimes those wires get chaffed and can ground out when the timing base moves

Sounds like its either the stator or timing base to me

Heres the troubleshooter EMD mentions
http://issuu.com/cdielectronics/docs...eshootingguide

 

[Bosunsmate]

To answer your other question, removing the flywheel is normally not hard, i did mine last night to degrease and grease the timing base as it was sticking.

You need a outboard flywheeler puller (look it up) it looks like a harmonic balancer puller. All it is is a device with three holes which you insert bolts through to attach to the holes on the top of the flywheel. You then turn the middle bolt with a crescent or socket and then in most instances the flywheel pops off unless the last person overtightened or something else has gone on such as a prior dimwit putting locktite on it.

The main thing is to make sure you get High tensile bolts for the flywheel threads. If they are too weak they will snap off and then you have to drill them out and retap...
Make sure they are in to near the end of the threads but dont thread them in too far that you screw down into the stator.
Once you have undone the nut, dont take the nut the whole way off as if the flywheel is on tight the nut will stop the flywheel kicking up fast and dangerously if it releases with a big pop.
Dont get gear pullers- the ones with big arms, they will bend the flywheel.
If its real stuck then give it a short gentle wrap on the top of the puller with a small sledge hammer- that often releases the very stuck ones. Just dont whack very hard.

Hopefully you will just get a nice easy one for your first time.

 

[matthieu]

Thanks guys, I'll definitely try to diagnose the resistance on the stator, also need to look for grounded wires because now that you mentioned it, at times, it will start firing again for no apparent reason. Might also be something mechanical, maybe the stator contacts are dirty but that would probably result in a consistent failure. I'll keep you guys posted, might not have a chance to test that before the week-end.

 

[matthieu]

No Title

Ok I think I found the problem in a corroded orange wire coming out of the stator. I was inspecting the wires for tear and when I moved this harness the wire just broke off. Is this even repairable? The harness seem to be embedded in the body itself. Advice?

Thanks

 

[Bosunsmate]

Yes thats a fault, ive repaired one of mine that did that.
You will need to pop the flywheel so you can get near the component and replace the line with tinned marine wire which you can get at most boat shops.
Do the others too and save you more grief down the track

 

[matthieu]

How do you crack the stator open to get to the wire? On mine the cables seem to run inside the body through a molded piece of rubber or something. The wire is broken right at the entrance.

 

[Bosunsmate]

How do you crack the stator open to get to the wire? On mine the cables seem to run inside the body through a molded piece of rubber or something. The wire is broken right at the entrance.

Ive never had one break that far in.
If you can scrape back the outer covering carefully you may be able to get enough to solder a joint, the only other option i can think of would be replacement, they arent cheap