78, 150 black max, no spark

[Kerry Graham]

I have had an intermittant loss of spark to all cylinders. I usually start the merc with the water muffs prior to fishing trip. The last two trips, would not start at lake launch. Bring it back home and set a few days, it will start up again? I took a close look at all of the ignition wiring, and replaced a few that had loss of insulation. I have been thinking that the trigger or stator may be the issue. Any thoughts or suggestions would be most appreciated

 

[merc850]

You can start by checking these values, I'm betting it's the trigger.

 

[QBhoy]

Hi. I have this very engine. Had a similar issue to you. Turned out it was the main fuse assembly holder under cowling on starboard side of engine.

 

[Kerry Graham]

Hi. I have this very engine. Had a similar issue to you. Turned out it was the main fuse assembly holder under cowling on starboard side of engine.

I would have never thought to look in that direction, I have it in my shop and will check the fuse center right away. Thank you for the response, I prefer to make my own maint and repair if possible.

 

[Kerry Graham]

You can start by checking these values, I'm betting it's the trigger.
View attachment 357745
View attachment 357746

I have not seen this chart before, I have done a few ohm readings on the trigger at the power packs, though I will check it all again, thank you so much for the response. I will let you know the results, I love this motor when it runs.

 

[QBhoy]

I would have never thought to look in that direction, I have it in my shop and will check the fuse center right away. Thank you for the response, I prefer to make my own maint and repair if possible.

Yeah. Did exactly what you describe. Intermittent too. Would show almost like a flat battery, slow starter and no bendix… and sometimes nothing at all. The fuse holder was only barely making contact with the fuse and very hot. The one om starboard side and fairly high up

 

[Kerry Graham]

I don't have a fuze of circuit breaker on my 150 blk max. The red cable from battery goes to starter solenoid, and black cable to bottom of starter. 1978 1500 V6. I may have a faulty ground wire on engine, taking a closer look.