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1987 Johnson 140 Stator

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Pmadewell

New member
Had a question about checking the resistance on my stator. At room temp, the resistance meets spec perfectly. However if I check it after running the motor the resistance is much higher and well above the acceptable range. Does this mean the stator is bad? I understand resistance goes up with heat, but didn't know if it was supposed to remain in the acceptable range when hot or if it was normal for it rise above? Thanks in advance for any insight on this.
 
It has a rough/irregular idle, RPMs will drift around a couple hundred. Also as the day goes on it developes a bog coming out of the hole. Once on plane (3000rpm and above), the motor runs absolutely perfect. It seems it would be an idle circuit issue, but I've cleaned the snot out of them and it hasn't changed a thing. To me it seems it's electrical since heat seems to make the issue worse?

*coils are good
*has new powerpack
*trigger checks out good per the ohm meter
 
Additionally, I checked the leads from the power pack to the coils, and I was only getting 4-6 volts on my DVA meter. Isn't there suppose to be 175V+ going to the coils?? Does seem like the motor should even run with those numbers. Is there something I'm missing here? Greatly appreciate any feedback.
 
Motor was rebuilt last winter, compression is 135 on every hole. Been through the entire fuel system, everything spotless and no air leaks. So now I have turned to the ignition side. Have not tested spark yet, though it does have fire on every plug. Been using DVA meter to try and figure out if the stator and power pack are performing as they should. Yes I put a new power pack on a few months ago, but these strange readings have me scratching my head. Kill switch is ok, no voltage coming through it. I'd like to diagnose this thing and not just throw parts at it. Motor ran perfect this spring, seems this issue started when the hot temps got here.
 
Retest your DVA reading as it would not even start with volts that low...it is normal for resistance to go up when it gets warm.
 
Thanks for the info guys. I have gone to the CDI site already and that is the info i used to test the system in the first place(and my service manual). I am using a standard multimeter with a DVA adapter, is this the correct set up? Got it on DC and range it correct, have no idea why it's giving me these low numbers as the motor does run decent, just slightly irratic at idle, and then the bog once warm.

As for the resistance, i do understand that it is normal to go up as temperature goes up. Just curious how much higher it should go? The service manual says 560 +-25. However after i run it, i get a reading of like 670, which is obviously well above the service manual range.

Thanks again for taking the time to respond to the post.
 
Still fighting this motor and I keep coming back to the strange voltage readings going to the coils. I'm still getting 5-7volts at idle. I've used two different meters and get the same readings. Surely this can not be right, CDI site says I should see 150+. Anyone have an idea of what is going on??

model J140tlcua
 
Pretty sure DVA readings are AC. The only systems that are dc on your motor are the starting and charging system. The ignition system takes it's voltage straight from the coils under the flywheel. Are you using a quality tester.
 
I thought it was AC out of the stator, and then DC from the power pack to coils? I got 500V AC out of the stator just now with the DVA.
 
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