my '85 75hp merc outboard lost spark

[colwllce]

i was having a problem with my fuel and i rebuilt my fuel pump. Then it fired up and one of the leads from the stator burned in half. It was one of the two yellow leads.I traced them back to where they appeared good and spliced in two new wires with heat shrink connectors and it ran fine. Took it to the lake later and ran fine for about 15 or 20 mins. Then it started bogging down and the more throttle i gave it the worse it was. to the point where i just made it back to the launch. tested it today and found that it has no or very little spark. It varies between the two but it will not start and I don't know what to check next. I've read a few places that it could have blown the switchbox. Someone please help. My first boat and my first day out.

 

[latin monkey]

Re: my '85 75hp merc outboard lost spark

check the condition of the wires going to the trigger

 

[JAY 22]

Re: my '85 75hp merc outboard lost spark

i'm no boat mechanic, but in my experience any loss of spark could be caused by a bad magneto, bad plugs, a bad coil, or a bad connection in the wiring. thats about all the help i can be but it's a start, considering no one has responded

 

[Speedwell69]

Re: my '85 75hp merc outboard lost spark

I would do a resistance test on the stator I recently had a problem with my 1984 60hp. The stator didn't test as it shpould so I changed it on the advice of someone on this site and now it runs.

 

[achris]

Re: my '85 75hp merc outboard lost spark

Buy/make/steal/acquire a DVA meter for testing outputs of the stator, trigger and switchbox. Once you have that you can then diagnose the problem properly and get the right part/s straight up. Ignition components CAN NOT be checked with just a resistance meter, you NEED a DVA. Yes, some people will get lucky and tell you they did and fixed the problem, but there are plenty who will try and fail that you don't hear about.

If you need to build a DVA click HERE. The parts will cost you all of about $5.... Money well spent when you think that if you buy a switchbox or a stator, and that's not the problem you've blown $300!!

Once you have your meter post back here and I'll dig out the test procedure for your engine and post it up for you....

Chris.........