stator failure causes

[mma01]

My OEM stator died on me at 40k km's last year. When I pulled it out, there were burn marks on the one of the windings. I replaced it with a Rick's Electric stator and everything was fine for 3k Km's, but now I have to replace it again!

My bike wouldnt start so I recharged the battery and measured voltage across the battery while revving the bike. It wasnt charging at 5k rpm. Next, I measured the resistance of the each of the pairs of wires from the stator and it came in below spec. Finally, I measured continuity between the wires of the stator to the chassis ground and determined that it shorted out.

I recently pulled the cover off and the clip that holds the wires clear of the spinning flywheel was still in place, so I dont think it rubbed through. I assume the regulator was good b/c at the time I installed the fresh stator, the voltage when charging was within spec. The battery is a year old. What are some possible causes for premature stator wear?

[JohnnyP636]

You stator does not bolt to the engine cover correct? Just asking because I know sometimes people have a little crash, and although the stator cover isnt leaking, the dowel pins get bent and the cover shifts. Making it off center and rub on the rotor...

[frekeyguy]

what voltage did you get across the poles?

[bitzz]

Seeing how he has already said the stator windings are shorted to the well grounded base he will get zero output.

If he hasn't damaged the stator the reason it is shorted is it wasn't insulated enough when it was made.
There is VERY small chance he could fix it by soaking the stator in di-electric paint.

[mma01]

You stator does not bolt to the engine cover correct? Just asking because I know sometimes people have a little crash, and although the stator cover isnt leaking, the dowel pins get bent and the cover shifts. Making it off center and rub on the rotor...

It does not sit behind the engine cover - it sits behind the flywheel, so a shifted cover shouldnt affect the stator at all. The strange part is that the OEM stator DID die shortly after a small crash.... I thought it was just a coincidence.

[strictlye]

check the rectifier, usually you want to replace both at the same time if you can.

Suzuki of brampton changed my stator under warranty when it died and didn't change the rectifier and it caused an electrical fire on my bike the next week. Good thing I got a free extended 2 yr warranty when I bought the bike.

[mma01]

check the rectifier, usually you want to replace both at the same time if you can.

Am I right to assume that if the charging voltage at battery poles after changing the stator is correct after changing the stator, the rectifier/regulator is fine???

[strictlye]

Am I right to assume that if the charging voltage at battery poles after changing the stator is correct after changing the stator, the rectifier/regulator is fine???

To be honest I don't know the specifics, I just know when my bike broke down and a mechanic (Rosey Toes I think or someone from his shop) came and got me and while we were talking he advised me of what the problem most likely was as I got the stator repleaced the week before. When I told him the stator was replaced he asked if the rectifier was replaced too and I said no.

I've spoken with many other mechanics who share the same view on changing both at the same time. I'm sure when SOB checked they thought it was fine hence why they didn't replace it initially but if its an intermittent problem and they over look it......well it could cause an electrical fire which it did on my bike. Freaked me on when I was in traffic and I saw flames shooting from out of my fairings under my gas tank. I kept thinking it was going to blow like in the movies.

ALSO......if you see fire/flames and you want to attempt to blow it out......take off your full face helmet first....its more productive that way.

[nobbie48]

Stator failure on Goldwings is usually blamed on corroded connectors between the stator and Reg /rec. The loose connections create wild voltages in the stator. Not unlike disconnecting a battery from a running motor can destroy an alternator.

[bitzz]

I wouldn't install a new expensive stator without testing the rectifier.

[mma01]

I wouldn't install a new expensive stator without testing the rectifier.

Ricks Electric, who provided the stator, has asked me to send back the stator.. hopefully they will replace it with a new one since its still within the one year warranty period.

There isnt anything mentioned in the yamaha service manual, which focuses exclusively on tests of the stator. It says if the stator passes all tests and the charging output is 14 volts, the rectifier is good. Any tips on testing the rectifier? I really dont want to have to change the stator again (the flywheel is a huge pain to remove)

[GP_RZ]

Make sure you check ,clean and grease all your Ground points.