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Control Module on 86, 4 cyl 75HP dead again

L

leachy

Contributing Member
So it seems I have killed a second control module and the boat didnt even get to run on the water. It seems the original one died somehow again between buying the boat and it sitting for a few month and the new replacement has done a similar thing. The last time I started the engine, second turn of the key after it kicked with the choke on and idled so smooth and ran perfect. When I went to just give it a run after sitting for a month and replacing the fuel tanks and fuel lines its screwed again. The only thing is the battery every now and then has been put on a trickle charge.

Any help here would be appreciated as this is a really expensive repair over herein Australia. Last time i replaced the trigger module for a sierra brand along with a genuine voltage regulator.

Regards
Leachy
 
I would have a real good look at the starter motor.----Take it apart , inspect and do an ohm test on the armature.----Very easy to do and costs no beer tokens.----Have the battery load tested.
 
racerone said:
I would have a real good look at the starter motor.----Take it apart , inspect and do an ohm test on the armature.----Very easy to do and costs no beer tokens.----Have the battery load tested.
Click to expand...
How does that effect the switch box module?
 
I am not an expert here, but it sounds like a stator issue...

For the motor to start, the motor must turn atleast 300 rpm to develop enough voltage to fire the plugs. Hence the starter/weak battery comment.

Here is a link to the CDI trouble shooting guide....

You will need a Volt meter with a DVA adapter....

My '86 Merc 60 hp, had the insulation on the stator leads falling off......

Better to test than throw parts at it....
 
FishinLite said:
I am not an expert here, but it sounds like a stator issue...

For the motor to start, the motor must turn atleast 300 rpm to develop enough voltage to fire the plugs. Hence the starter/weak battery comment.

Here is a link to the CDI trouble shooting guide....

You will need a Volt meter with a DVA adapter....

My '86 Merc 60 hp, had the insulation on the stator leads falling off......

Better to test than throw parts at it....
Click to expand...
Its the same issue as last time, except last time I replaced the stator and rectifier. I replaced the stator in wishful thinking seeing it was the cheapest part and replaced the rectifier once it was running again after replacing the switchbox so everything was new. The switchbox was secondhand but worked fine. The motor was spinning at normal speed way above 300rpm its just that the spark has gone again and I assuming its the switchbox. I will check the résistance of the stator leads when I get the chance but that was brand new Sierra aftermarket item.

Im just wondering what fault or wiring issue / bad battery or any kind of arking could cause a swithbox to blow.
 
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