Replacement rotor won't work

[jb57]

Howdy yall, So I've got a bone stock 81 650 special II, and I've been having problems with the charging system, if you'd be able to help me out. After replacing the worn out brushes and testing the regulator/rectifier, I've traced the problem to the rotor. The stock one registers les than one ohm on my multimeter, and the one that I got from a salvage yard is from an 82, and reads about 6 ohms. I put the salvage one on, and the bike won't start. I made sure the alignment mark was correct on the replacement compared to the stock and put it on and tightened it up and put the stator and clutch cover back on. It backfired a couples times without starting, and then I stuck the old rotor back in that won't charge, and it fired right up. I tried kickstarting it and electric start, and nothing doin, either way. Any ideas? Is my timing off somehow, or did I just get a screwy rotor?

 

[650Dave]

You may have the trouble that I had recently with NEW replacement rotor. When it got hot, it would miss at low speeds. The problem was that the magnet that triggers the TCI was bad. Putting a small rare-earth magnet on top of the original solved the problem for me. Dave

 

[jb57]

Where is the magnet, is it on the back of the rotor? What do you mean rare earth magnet, where can i get one? I'm kind of new at this stuff.

 

[gggGary]

 

[XSLeo]

Radio Shack I can't find my package they came in so I can't give you the part number. It's a two pack of 4 mm-3/16 inch rare earth magnets. I think $1.99 or $2.99 for the two pack.
You'll need some JB Weld to "glue" the magnet on to the rotor. The regular not the Quick Set stuff.
Let the magnet stick to the rotor magnet to line up the polarity. Then Mark the top of the magnet with a red magic marker, pull it off. Clean the rotor magnet and the RS magnet very well. If not very clean the JB weld won't hold well.
Now mix up a small dab of JB Weld, apply to rotor, put magnet inplace red side up, centered on the rotor magnet. A bit more JB Weld around the magnet. Let cure over night.
Leo

 

[gggGary]

Remove your stator and make sure it was seated fully and straight. Charge your battery fully also.

 

[xjwmx]

People with a magnet problem need to look into magnet recharging instead of capping another magnet on top of the old one. It's just a neater solution.

 

[jb57]

The replacement rotor's from an 82, and I don't see the magnet on it, can you help me out?

 

[gggGary]

That might be why the bike was in the bone yard. instead of out cruising the highways

 

[xjwmx]

Take it back and tell them it's not from an '82 then. '80 and up have the magnet. Without the magnet you won't get a spark with the stock ignition.

 

[jb57]

This is the rotor that I bought, does it look like its pre-80-84?

 

[gggGary]

Yup wrong rotor.

 

[jb57]

Thanks fellas. I'd say that's my problem.

 

[Brian902]

JB here is a site with manuals that you can save as a pdf file and have for reference. Read lots, learn lots and then ask questions.

www.biker.net

Good Luck.

 

[xjwmx]

^I'm sure he sees the difference. He wanted confirmation that something wasn't in play that he didn't know about as a newb. And what's your point?

 

[XSLeo]

When you take it back print out the pic of the right one and take it along so they know the difference.
Leo