Yamaha Grizzly ATV Forum banner

Testing the Charging system on '98 Grizzly

3487 Views 4 Replies 2 Participants Last post by  KArthur
On my '98, it does not seem to keep the battery charged. I have jumped out the cooling fan so that it runs continuously when the switch is "ON". I didn't like doing this, but I could not get it to turn on when the engine got hot. I suspected the stator coil might be an issue, b/c when I got the bike, someone had been inside it and actually broke one of the wires. I repaired it and tested it the best that I could.

I have a service manual and did the ohm test for the stator coil. The test showed the resistance at 1.2 oms. A little out of spec (should be .70 to .86). Next, I connected my volt meter to the battery and started it up. If I hold the rpms around 2000-3000, the voltage on the battery steadly climbs up to 13.5 volts. Thats as high as it goes. The service manual says it should be 14V @3000 RPMs.

I changed out the regulator with a different one and the voltage test shows the same thing.

1. Is this "normally" how the voltage will change? I mean, does it gradually increase up to a certain point. Even when I let it idle back down, the voltage stayed at 13.5 volts. I expected to see it go up/down when I rev'd the engine.
2. Even with my lights on (with the engine running), the voltage on the battery stayed at 13.5v. So from this test, am I correct in saying that the battery is actually taking some charge? Its a little low, but definitely not discharging as its running.
3. I have a 2000-Big Bear 400 that I can use for parts. I think the stator on it is good. Only difference (maybe) is the plug. I think I can just change out the plugs and I will have a good stator.

See less See more
1 - 5 of 5 Posts
You answered your own question. The resistance checks are out of tolerance to the manual, so the stator is bad.
A bad stator will do exactly what's is doing. Slowly rising voltage to a lower peak.

My 1998 600 would charge at over 14 volts at above idle rpm.
  • Like
Reactions: 1
Thanks. The rotor assembly on the 2000-Big Bear 400 and my '98 600 Grizzly are the same (4KB-85550-11-00). Other than the plug being different, do you think I can use the stator out of this one?
Thanks. The rotor assembly on the 2000-Beg Bear 400 and my '98 600 Grizzly are the same (4KB-85550-11-00). Other than the plug being different, do you think I can use the stator out of this one?
Should be fine if the stator itself is the same. Check the resistance levels before installing to be 100% sure.
I just found the SM for the Big Bear and the coil resistance is the same as my Grizzly (.70 to .86 ohms). The service manual says the charging voltage for the Big Bear is [email protected]1000 rpms. Wonder if that is a typo in the manual and should be 3000 rpm (like the Grizzly SM).

Not sure that it would even idle that low.

1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.