Ignition?

[Tomstuchlik]

I have a 1989 merc in-line 4. The boat runs great for first 10-15 min. Then the motor loses power and misses out and struggles to gain power but seams to run good below 2000 rpm. I check stator ohms all normal except one which reads 7500 on a 7000 max. I checked trigger ohms. One is within range (brown to black) but other is extremely high, 101000 ohms on white to black. Will a bad trigger being causing my problem?

 

[gm280]

:welcome: to iboats Tomstuchlik. Always nice to have a new member...

Sure sounds like a heat issue. And since you are reading things out of range, it might be time to look for some replacement items. Not being there and reading and checking things myself, I can't state that you need to replace any part. But it does point to a suspect item all the same. Have you tried to read the resistance cold and hot? JMHO

 

[Tomstuchlik]

I have been informed that my mercury maintenance manual swaped some testimg information. Based upon this, the trigger ohm are in range. I am now going to check the stator voltage output but I need a DVM. The TEC suggested lifting the stator leads off the reg and see if the is any improvement. He had ran into some strange situations where the reg causes some issues with the stator. I am going to check these two suggestions next. Thoughts?