Does anyone know how to check the rectifier and stator on a 400ex? The book talks about doing it by cranking the motor over, but I want to know of a way to check it with an ohmmeter. Does anyone know the resistance specs of these?

 

to check stator with an ohmeter all you do is unplug the stator and check stator lead to stator lead. I don't recall what kind of stator it has but a 3phase has 3 leads, full wave has 2 leads and half wave has 1 lead. really you need to do a voltage check to see if the stator is working properly. You test the leads going into the rectifier by putting the multimeter in diode function and put positive lead to positive on the rectifier and negative lead to each stator lead going into the rectifier. reverse and put negative lead on the rectifier positive and positive to each stator lead going into the rectifier. now test the other side of rectifier and put positive lead on the negative lead of the rectifier and negative lead to each of the stator leads going into the rectifier. reverse and do it the other way negative to negative and positive to the stator leads going into the rectifier. half of the tests you should get a number .2-.8 ohms and the oter should be offline or infinite resistance.

by the way how did you come to the conclusion that you needed to check these parts. did you test the rest of the system and what were your problems that you were having with your 400ex

 

I have no spark at the plug. I tried changing the module, that didn't work. I checked the coil, it's fine. I thought the rectifier was part of the ignition system, but it's not. So all I needed to check now is the stator. I did that last night and it showed it was ok.

 

Well, I finally found the problem. The dang black/red wire that goes to the CDI had a bad connection. Well, at least I learned how the ignition system works [img]i/expressions/face-icon-small-smile.gif[/img]