91 40 hp stator wire volts drop from 14 volts-4 volts after running for 10 minutes

[rjrobin2002]

I just fixed a shorted trim wire problem and the boat is still running bad. My boat will run great for about 10 minutes and then it will only idle after getting warmed up, the idle is ruff. I checked the voltage coming from the stator wires with the boat just cranked and I got a 14.8 volt reading at idle. After about 10 minutes it starts running bad and I now have only 4 volts coming from the stator. Is this pretty much a sure sign I have a bad stator coil?
I am thinking of ordering a stator coil, coil pack, and rectifier to make sure I have a good electrical system.

 

[rjrobin2002]

Re: 91 40 hp stator wire volts drop from 14 volts-4 volts after running for 10 minute

Correction, my voltage check is from the red wire leaving the rectifier with DC. It will produce 14.8 volts for about 10 minutes and the the volts drop to 4. Is this rectifier or stator?

 

[rjrobin2002]

Re: 91 40 hp stator wire volts drop from 14 volts-4 volts after running for 10 minute

I ohm checked my rectifier today and it checked out OK. I cranked the motor and it was running bad from the start, I checked the AC volts from the stator and got 6 volts at idle and with it reved up I got a 17 volt max. From what I read I needed 20-25 volts to have a good stator. My engine runs bad when these volts are low, so I have some sort of ignition and charging problem. I checked the flywheel magnets and all of the wires with no shorts to be found.

 

[rjrobin2002]

Re: 91 40 hp stator wire volts drop from 14 volts-4 volts after running for 10 minute

I found a complete timing/stator/coils/ingintion module on ebay today that is on my way. This should fix my problem unless I have a bad harness. Seems like alot of people on here are having problems with charging and ignition problems at the same time, even though they are on different circuts with no one having a good explanation.

 

[killingtime]

Re: 91 40 hp stator wire volts drop from 14 volts-4 volts after running for 10 minute

Im in the same boat my parts will be here thursday so we might be fishin by sat. i have crazy weak spark and when a checked my stator was out of specs. best of luck