No spark on merc 140 1979

[Garth.306]

I have a 1979 merc 140 that has no spark. It turns over fast with new battery but no spark on plugs. If I remove all the plugs so there is no compression while cranking it will spark. I've also noticed it looks almost oily under stator does this mean my stator has failed and is not putting out the power required to run engine? Possibly a recifier also?

 

[Little Richard]

Engine needs to turn at least 250 rpms for enough voltage to be produced for the ignition components to operate. Your battery connections need to be clean. Your starter might be dragging. Bad battery cables. If all is fine your trigger could be weak. Google cdi electronics trouble shooting guide.

 

[Little Richard]

You will need a DVA adaptor to test your stator voltage. A bad ground will ruin your rectifier. And once it's toast can cause your stator to overheat. Might be what you see under stator. That site will show you how to test all this.

 

[Little Richard]

I'm not familiar with mercs but have been learning on this old evinrude. I would think the principals are similar

 

[Chris1956]

Does that motor have a single coil and a distributor or 6 coils? 1979 was the crossover point for the two different ignition systems.