1982 115hp, how to bench test the stator

[Evinrude Boater]

I've got intermittent spark all of a sudden on 2, 4 and 6. Seems to have started right after the boat took a jump off a wave. Could the switch box be causing that? 1, 3 and 5 seem to have steady spark. Is there any way to test it besides switching the the switch boxes?

 

[turbinedoctor]

Re: 1982 115hp, switch box work intermittently

Re: 1982 115hp, switch box work intermittently

It seems a bit of a pain but that would be my first route of troubleshooting. You can check to see if the trigger wire to the other switch box came loose.

 

[j_martin]

Re: 1982 115hp, switch box work intermittently

Re: 1982 115hp, switch box work intermittently

It seems a bit of a pain but that would be my first route of troubleshooting. You can check to see if the trigger wire to the other switch box came loose.

A bad stator will take down one bank. A bad trigger will take down one cylinder on each bank. (opposite in timing) A bad ground might shake loose when you hop a wave, and anything can happen. That's where to start.

Otherwise, it's cheapest and best to invest in the proper test equipment and a service manual and systematically diagnose the problem.

hope it helps
John

 

[Evinrude Boater]

Re: 1982 115hp, switch box work intermittently

Re: 1982 115hp, switch box work intermittently

Found a loose ground from harness to ignition mounting plate but no difference noted when fixed.
Switched red and blue wires from stator to switch boxes and the problem switched from 2, 4 and 6 to 1, 3 and 5. Took the flywheel off and it looked like the flywheel magnets scrubbed the front plastic part of the stator. It looked melted and there was a thin layer of plastic melted onto some of the flywheel magnets.
How can the stator be bench tested?

 

[Evinrude Boater]

Re: 1982 115hp, switch box work intermittently

Re: 1982 115hp, switch box work intermittently

The shop wants $70 to test the stator. Ouch!! How is it bench tested. Can it be fully tested without spinning the flywheel around it?

 

[j_martin]

Re: 1982 115hp, how to bench test the stator

When you swapped the stator charge coil wires from pack to pack, and moved the bug, you proved the stator was bad. Additionally, it has been hit by the flywheel. Any strike will likely move a lamination laterally into the winding, shorting the stator. That begs the question.
HOW DID THAT HAPPEN?

Either the stator mount bolts came loose, the flywheel was dead loose, A magnet is out of place, or the top main bearing is bad. There should never be any contact between the stator and the flywheel.
edit ..... I guess the top bearing cap could be cracked.

Fix what caused the strike, put in a new (to you, used is fine) stator, and yer good to go.

hope it helps
John

 

[Evinrude Boater]

Re: 1982 115hp, how to bench test the stator

Everything looked fine, no play in the crank, nothing loose, no debris. Might have been damaged or scrubbed previously and finally gave up.
I read the trigger should also be replaced at the same time as the stator. Do you agree with that added expense?

 

[j_martin]

Re: 1982 115hp, how to bench test the stator

Everything looked fine, no play in the crank, nothing loose, no debris. Might have been damaged or scrubbed previously and finally gave up.
I read the trigger should also be replaced at the same time as the stator. Do you agree with that added expense?

No, the trigger should not be hurt. One caveat is look at the wires coming out of the trigger, and if they are getting to be marginal, then you might as well change it now instead of later.

You said there is sign of a strike on both the stator and the flywheel. Until you figure out for sure how that happened, you may be throwing good money after bad.

hope it helps
John

 

[Evinrude Boater]

Re: 1982 115hp, how to bench test the stator

I wonder if rust build-up on the flywheel magnets could have caused the contact with the stator. The boat has been sitting unused for several years.
Both yellow wires to the rectifier have split insulation and exposed wire. They could have been shorting I suppose. There was fuel residue on top of the engine from a split drain tube down the sb side. Possibly the fuel helped to conduct voltage.