Problem starting after changing stator and rectifier

Good afternoon,

I'm having issues trying to identify what the issue starting my 1997 Johnson 40 hp. So initially, I replaced the stator cause it was determined that it was defective. Then the motor started fine but was overheating and was determined that the rectifier/regulator was defective which was causing voltage to go to the stator. I double checked the stator and the resistance was still fine on all wire and still produces voltage.

My new rectifier arrives, I plug everything in and now it doesn't want to start at all. There is no fire at the spark plugs at all and disconnected the kill switch wire to isolate that and still no spark.

Now I tried to see if there was power coming out of the orange/blue wire (coils) and I guess you need a peak voltage multimeter cause I was getting between 0.5 volt to 1.7 volt when cranking.

Should I disconnect the rectifier/regulator and see if that works or is there another way to check the power pack. Or does anyone have any idea what could be the issue.

Re: Problem starting after changing stator and rectifier

Another quick question? Do you need a peak voltage adapter to check the voltage coming out of the stator?

Re: Problem starting after changing stator and rectifier

excalius said:

.... Then the motor started fine but was overheating and was determined that the rectifier/regulator was defective which was causing voltage to go to the stator.

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It would be extremely interesting to hear how a rectifier is related to the engine overheating.

Do you need a peak voltage adapter to check the voltage coming out of the stator?

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Yes. If you're handy with a soldering iron you can make one for just a few dollars worth of parts. I've seen schematics for one in a few places, search for 'DVA adapter'.

It would be very helpful for you to get a factory service manual. Not a generic, aftermarket manual but the original one put out by OMC. They're usually available on ebay for $30 or $40 and are worth their weight in gold.

Re: Problem starting after changing stator and rectifier

Lessons In Electric Circuits -- Volume III (Semiconductors) - Chapter 3

see section on DVA "PEAK DETECTOR"

DVA is a fancy term meaning "READING AC VOLTAGES WITH A DC METER"

To do so you need to rectify AC (via a diode) and stabilize using a capacitor to store and "average out (ie: flatten)" the DC peaks out of the diode.

The meter set to DC volts will then interpret the AC peaks as a steady DC voltage...
Personnaly I like old style "needle" meters which by the very nature of their mechanical movement tend to introduce some damping effect

(fancy modern digital meters do a lot of signal sampling and sometimes go nuts trying to display a fluctuating signal)