1989 Johnson GT 150 Stator Problem????

[campione 2308]

I am not having problems starting and it runs strong, but I noticed the black box( do not know what is is ) in the front of the motor on the Stator is melting. There is a hard shiny substance on the wires and the power head. What does this box do and what should this melting be affecting? The one on the back of the motor is clean and intact. The volt gauge shows 13 to 14 while running and I do not notice any kind of miss in the motor. I have noticed a 300 rpm or so drop at wot on occasion. I looked at all the plugs and none of them were wet or fouled. Any help would be appreciated as I am getting ready to take the boat on Vacation for a week.

Thank you in advance,

 

[HighTrim]

Re: 1989 Johnson GT 150 Stator Problem????

Could you post a pic?

I would check the spark to ensure that you are not dropping any cylinders. The spark should jump the gap on an inline tester a good 7/16 of an inch with a bright blue ZAP!!

 

[campione 2308]

Re: 1989 Johnson GT 150 Stator Problem????

Chris,

I checked the spark . Nice bright blue spark. I suppose it could drop as engine warms which would also burn the plugs back off. Do you know if the black box in the front goes to the charging system? I am assuming that it does since there are 2 in the rear. I do not have any pics available, but I will try to get one. I am assuming that eventually I will lose resistance across the stator and the real effects will start to show, but I do not know how long that will take as I do not know how long it has been melting down.

 

[campione 2308]

Re: 1989 Johnson GT 150 Stator Problem????

Is it possible that the coating has just melted ???? Is there a way to test the stator ?

 

[emdsapmgr]

Re: 1989 Johnson GT 150 Stator Problem????

You may be referring to the rectifier/regulator which is under the flywheel, nested between the two cylinder banks at the top of the engine. It is part of the charging system and is water cooled from the bottom. I'd be careful if you have anything melting with the electrical system on this engine. I'd spend proper time and get it diagnosed yourself, or have a skilled tech look at it. You don't want to have an electrical fire under the hood.

 

[campione 2308]

Re: 1989 Johnson GT 150 Stator Problem????

Thank you for the advise. I am not sure that this is inbetween the power heads. It looks to be part of the stator with 3 coils of wire on either side. The substance on the power head looks like a shiny black plastic or epoxy like. I quess I need to pull the fly wheel get a better look. Is there a way to test the stator and what shoul the results be ?? What would cause one to melt down if that is the case?

 

[CharlieB]

Re: 1989 Johnson GT 150 Stator Problem????

Individual coils on the stator have been 'potted' with an epoxy thype of thermoplastic to insulate/protect the windings.

Over the years manufacturers have begun NOT coating these coils/windings as the pastic/epoxy coatings have been known to melt off, making a mess. Also, the additional insulation retains heat shortening the service life of the stator.

Your stator is of the 'potted' styple.

It is still woriing, currently, but it does run at a pretty good temp. One day, who knows when, it will fail and you will have a 'no spark' condition. When that happens, then you will follow the troubleshooting guide to BE SURE that it is the stator at fault, then replace it.

In the mean time, if it ain't broke.........

 

[campione 2308]

Re: 1989 Johnson GT 150 Stator Problem????

Thank you Charlie B.....Is it possible that only the very front coil was potted?

I can clearly see that the rest of the coils are not and were not potted. My model is a J150STLCE. I have noticed that only the 1989 and 1990 used the same 35 amp stator. I have not pulled the flywheel yet but, it looks like the very front is a square box with 3 coils of bare copper windings on each side and 2 black boxes in the rear. I say black boxes, because they do not look like coated or wraped coil windings. I have seen pictures of the potted stators and mine does not look like them at all. Is there anything on the stator other than coils of copper winding???? Everything seems to be checking out OK, but there is obviously a problem. I have checked the stator according to the Clymer manual, but I did not have the brand of meter that they said to use. Is there a quick way to check the stator with a standard digital meter???

 

[emdsapmgr]

Re: 1989 Johnson GT 150 Stator Problem????

If you are still unsure what the component is that is melting, check out the OEM parts lists to identify the specific part. You can find the OMC parts listed for your engine online at epc.brp.com. Let us know what you find out.