I got a 81 xs650 that I took apart and painted the motor and frame. When I put it back together it was was running fine. I was having charging issues so I replace the rectifier/voltage, alternator rotor and stator bushings. Now the bike is back firing and running rough. I'm getting 14 volts when I rev the motor, so I assume that was the charging problem. I'm not sure what the issue could be now. Does anyone have any ideas what the issue could be.
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Motorcycle back firing and running rough after replacing alternator rotor
- Thread starter Timbuktu
- Start date
-
- Tags
- electrical engine
The rotor contains the trigger for the ignition. Is it properly installed?
When you replaced the rotor, are you sure that the woodruff key was still in place, and that the new rotor mated to the key?
Some lads are buying new rotors, and finding that the small magnet, embedded into the rotor, is weak. Buying used rotors, of course its also possible to have a weak magnet. These small magnets are what triggers the transistorized ignition to fire the plugs.
Try reinstalling the old rotor, as a test, to see if the engine runs normally. If it does run OK, then you know you have a weak magnet.
Radio Shack sells rare earth magnets, that can be glued on top of existing magnet.
Use the Google Custom Search found in the upper left corner, to search for "rare earth magnet" threads..
Some lads are buying new rotors, and finding that the small magnet, embedded into the rotor, is weak. Buying used rotors, of course its also possible to have a weak magnet. These small magnets are what triggers the transistorized ignition to fire the plugs.
Try reinstalling the old rotor, as a test, to see if the engine runs normally. If it does run OK, then you know you have a weak magnet.
Radio Shack sells rare earth magnets, that can be glued on top of existing magnet.
Use the Google Custom Search found in the upper left corner, to search for "rare earth magnet" threads..
Painted motor and frame? Might want to check the grounds.
Brian902
XS650 Junkie
Tim,
when I painted my motor and frame I used one of the triangle motor mount plates at the rear as a ground point.
Clean the hidden back side of the plate to bare metal at two points, one for the frame and one for the engine.
Then clean the engine point of contact and the associated frame contact.
Bolt the plate back on, all is hidden, and you now now you have a good engine to frame ground point.
Some years had a ground, #6 cable, from one engine case bolt by the oil filler cap to the negative terminal of the battery to do this same job.
Battery ground from negative battery terminal to frame under the seat is ultra important to be clean and solid.
Grounds are super important and often overlooked.
.
when I painted my motor and frame I used one of the triangle motor mount plates at the rear as a ground point.
Clean the hidden back side of the plate to bare metal at two points, one for the frame and one for the engine.
Then clean the engine point of contact and the associated frame contact.
Bolt the plate back on, all is hidden, and you now now you have a good engine to frame ground point.
Some years had a ground, #6 cable, from one engine case bolt by the oil filler cap to the negative terminal of the battery to do this same job.
Battery ground from negative battery terminal to frame under the seat is ultra important to be clean and solid.
Grounds are super important and often overlooked.
.
Brassneck and Brian902...................Timbuktu said "When I put it back together it was was running fine". His present problem is not from painting motor and frame.
Brian902
XS650 Junkie
Right On Retired. OOPS!
Always a good idea to babble on about grounds though.
He could have a bad rectifier ground.
But more likely a bad magnet or his pickup or TCI have gone wacky.
Hopefully just a magnet issue.
.
Always a good idea to babble on about grounds though.
He could have a bad rectifier ground.
But more likely a bad magnet or his pickup or TCI have gone wacky.
Hopefully just a magnet issue.
.
Ya, I noticed that too...but he said it was having charging issues... which to me means that it would be wise to rule out the grounds and all assumptions therein.
Ya, I noticed that too...but he said it was having charging issues... which to me means that it would be wise to rule out the grounds and all assumptions therein.
I can't follow your logic. After replacing the rotor and rec/reg etc., he said he was seeing 14 volts, so he solved his charging problems.
Hi Retired,
I'm not worrying about the charging issue... and likely it's not a ground issue he's having...but since putting the bike back together (after paint) he said it was a) having a charging problem and b) running rough. He fixed the charging issue (sounds like), and I personally think the issue is with the timing, but my point was to rule out any grounding issues that MAY exist...either with the rotor or anything else...since we don't know more about his set-up (other than an 81), it may have sat with gummed up carbs, may have straight pipes, pods, etc...
I think it's pretty good advise.
I'm not worrying about the charging issue... and likely it's not a ground issue he's having...but since putting the bike back together (after paint) he said it was a) having a charging problem and b) running rough. He fixed the charging issue (sounds like), and I personally think the issue is with the timing, but my point was to rule out any grounding issues that MAY exist...either with the rotor or anything else...since we don't know more about his set-up (other than an 81), it may have sat with gummed up carbs, may have straight pipes, pods, etc...
I think it's pretty good advise.
Thanks for all the advice. It turns out the rotor I got from Mikesxs is junk. The magnet in the rotor was installed in the wrong spot or the key way is wrong. I ended up moving the ignition pickup. I had to drill and tap new mounting holes in the stator housing. Mikexs sent me two stator housings and both of them didn't work. I ended up using the original housing. Now I know why Mikexs has a disclaimer on electrical parts and a no return policy.
Mikesxs continues its tradition of selling many bad parts, that are unusable. No quality control in those Chinese/Taiwan plants.
^ Yes what RG said.
If you find break-up or miss firing later another rare earth magnet epoxied on top of the existing magnet may help.
If you find break-up or miss firing later another rare earth magnet epoxied on top of the existing magnet may help.
To the one already on/in the rotor.
