I have been tinkering on this for a over a year now and really want to get it all back together and working properly. It’s a 1987 TRX250 quad, 2×4, and it’s not charging the battery. I am an electrician and have isolated the problem to the alternator. I have checked the original stator and it measured fine, about .5 ohms between yellow wires, but decided to change it anyway, result…same thing, only getting about 5-6VAC out of the yellow wires at 3000 or more RPM. The only other thing that I can think of is the flywheel with the magnets, either weak or broken under the shield. The machine starts and runs fine so I know the pulse section is good. When I got the machine, the starter was missing and the starter gears had teeth missing and had fallen inside the crankcase and the little bits of teeth had rolled around between the stator and flywheel gap, causing some little dents and scrapes on the inside of the flywheel. I can slide a screwdriver around the inside and feel 12 definite gaps in the magnets, which seems okay…but maybe not. ?? :unsure:

See pics…

Any thoughts??

Thanks all.