Rotor Testing

[dubepj]

Installed new rotor about a week ago from Rick's. Bike still running and charging good. Checked my new rotor again, Ohms between the two rings is 6.4. seems to me that it was less than that when I first installed it. Maybe 5.7 or so. Is this a sign that it's on it's way out?? What could cause the rotor to change ohms reading? Still charges fine but I'm worried it's going to fail again. Thanks a lot for you input.

 

[Jim]

Installed new rotor about a week ago from Rick's. Bike still running and charging good. Checked my new rotor again, Ohms between the two rings is 6.4. seems to me that it was less than that when I first installed it. Maybe 5.7 or so. Is this a sign that it's on it's way out?? What could cause the rotor to change ohms reading? Still charges fine but I'm worried it's going to fail again. Thanks a lot for you input.

Temperature will affect resistance. How much of a temp change between readings?

 

[dubepj]

It was Probably warmer when testing first time. But not a lot different. Jim, in you opinion are Rick's rotors good quality, Also is a 6.4 Ohms reading any reason for concern??

 

[Jim]

I'm hesitant to knock Ricks rotors because as a rewinder of rotors... it could be seen as bashing the competition. Since I state so in my rewind thread, I will go so far as to say I won't rewind aftermarket rotors. And Ricks rotors are aftermarket. 'Nuff said.

6.4Ω is definitely outside the "book" range. Doesn't give you a warm fuzzy, does it...

 

[Oldfartaussie]

6 month's ago my rotor fell apart and I got it replaced cost free as it was only 6 months old. Starter wouldn't crank yesterday and I removed the left engine case to see three of the screws holding the front face of the rotor onto the rotor had come loose pushing the small black caps out in the process. No damage so I applied loctite to the screws and tightened them up. Seems OK, starts with Starter straight up, haven't had a chance to check if it's charging. Why are these rotors failing apart, anyone had this happen. Supplier has never seen it before.

 

[gggGary]

6 month's ago my rotor fell apart and I got it replaced cost free as it was only 6 months old. Starter wouldn't crank yesterday and I removed the left engine case to see three of the screws holding the front face of the rotor onto the rotor had come loose pushing the small black caps out in the process. No damage so I applied loctite to the screws and tightened them up. Seems OK, starts with Starter straight up, haven't had a chance to check if it's charging. Why are these rotors failing apart, anyone had this happen. Supplier has never seen it before.

What brand/supplier?

 

[GLJ]

If it charges it works. I would keep an eye on it. Maybe add a volt meter to see what it's doing as time and miles go on.
If it fails I would spend what is necessary to get @Jim to send you one.
Lot of threads on the aftermarket rotors failing.

Supplier has never seen it before.

Of course, would you expect them to say anything else.

 

[650Skull]

6 month's ago my rotor fell apart and I got it replaced cost free as it was only 6 months old. Starter wouldn't crank yesterday and I removed the left engine case to see three of the screws holding the front face of the rotor onto the rotor had come loose pushing the small black caps out in the process. No damage so I applied loctite to the screws and tightened them up. Seems OK, starts with Starter straight up, haven't had a chance to check if it's charging. Why are these rotors failing apart, anyone had this happen. Supplier has never seen it before.

That's 2 the supplier has seen now.............Never seen it before the first or second...........Read your first post of your first thread. Geofs still has 17 Points rotors, (Oz XS.s had points on 80 and 81 oz models), for sale, if it is a bad batch it should be made known

 

[Oldfartaussie]

I got both of the rotors from Geoffs xs and he said they come from Japan and they have both come apart, the first one shearing off the brushes. Geoff asked if I was fitting it correctly, and as I said it sits on the woodruff key and tightened up. Perhaps it is the vibrations ?

 

[Oldfartaussie]

Received used rotor from Geffs xs, he still has 17 new ones in stock, and it ohms out at 5.7. Installed rotor and getting 13.8 v at the battery at idle. When I replaced the rotor cover plate I must have left the screws loose as the plate fell off riding home from work and got run over and destroyed. I made one out of a blank cd holder case from when the kids were young until I can get another case plate. Heavy rain on the ride to work yesterday, over one foot deep on some of the roads and the plastic cover did not leak.