Hi, I had a problem with my 1997 trail boss 250 not charging the battery. A friend suggested it could be the stator. I took the flywheel off to make sure I had a good look at it so I would get the correct replacement. I started taking the stator out, but decided to test it before I bought a new one. It checked out, so I replaced the regulator/rectifier. That solved the charging problem. When plugging in the yellow/red wire from the regulator, I noticed there is an open terminal in the box. I think it is for the models with the bigger amp stator. These stators have an additional brown/yellow wire that mine does not have. I think the Magnum 400 had regulators with 4 wires. Anyway, I didn't happen to notice this open terminal when I unplugged the old regulator. Now I'm wondering if I have the yellow/red wire plugged into the correct terminal. There are three. The bottom terminal has a white wire plugged into it. I don't know if I should plug my yellow/red wire into the top terminal leaving the center terminal open or if I should leave the top terminal open. Anyone know?


Now that I had to put my stator back on, I think my timing is off. I've had it off before when I replaced the seals. I lined it up with the mark I made, but it just doesn't sound right and the engine was vibrating. I advanced it some and it quit smoking and seemed better, but has a tapping noise. I've never used a timing light before. I know how they work, but not sure how to hook up a tachometer to it so I can check it at 3000 rpms. I can keep guessing until I get it closer, but I'd rather do it the right way.

 

Ok back up a minute.. Is it charging back to the battery the way you have it plugged up? Plus if you didn't loosen the stator plate no way the ignition timing could be off unless the flywheel key is sheared and the flywheel has moved.Plus this is the correct regulator you should be using.http://www.ebay.com/itm/Rectifier-Regulator-FITS-POLARIS-ATV-4060193-4060087-NEW-/290486749433?hash=item43a25c08f9&vxp=mtr

 

Yes it is charging with the way it is hooked up now which is with the yellow/red wire in the middle. It looks exactly like the picture you posted, both my old one and the replacement I bought. The top terminal is open right now. I took the stator off, so yes, the bolts were loosened and removed.

 

Wouldn't worry about the extra wire as long as it's charging and yes the 250/300 have a 150 watt alternator,when you get to the Explorer 400 and the 4 stroke machines, alternators jump to 200-250 watts. Only correct way to check timing is to have a timing light and an accurate rpm gauge. You have to crank the engine,get it to 3000 rpms quickly and if set right the center line on the flywheel(25 degree BTDC mark) and case pointer will line up. If advanced or retarded,flywheel needs to be removed and stator plate adjusted and timing rechecked. Plus on the tapping noise do a compression check. Slapping noise may be piston slap.

 

just an update. I bought a timing light and checked the timing. It was too far advanced. Now it's right and runs like a champ again. Thanks for the help!

 

Good deal.. Timing needs to be spot on for any engine to run right.