charging rotor ..fix

[malc]

hello all thought i would share this with you..i was suffering with charging problem on my 81 it was the rotor 0.5 ohms so i got a after market one off ebay .it started and charged fine but after 30 mins it wouldnt rev up got it home in the morning started and ran fine for 10 mins then wouldnt rev up again checked all mesurments and all was the same as old rotor exept the magnet power it was really febble in desperation i drilled out the magnet what was 6mmx2mm after a lot of searching i found a very strong fridge magnet 6mmx5mm i drilled the backerlit deeper to 5.5mm put in chemical metal and pushed magnet in flush checking the pull on the magnet was the same field as my original the magnet was the wrong way in on the new one started perfect 800miles all is exellent hope this may help others cheers

 

[XSLeo]

Just "gluing" a Radio Shack magnet onto the magnet in the rotor fixes that problem too. No drilling. JB Weld works well for this. The Radio Shack rare earth magnets cost $1.99 for two.
Leo

 

[malc]

yeh i read a post saying that but was unsure about the clearance between rotor and pickup also the pull on the new magnet rotor was the wrong polarity compared to the original rotor magnet didnt know if that made any diffrence many thanks

 

[glennpd]

hello all thought i would share this with you..i was suffering with charging problem on my 81 it was the rotor 0.5 ohms so i got a after market one off ebay .it started and charged fine but after 30 mins it wouldnt rev up got it home in the morning started and ran fine for 10 mins then wouldnt rev up again checked all mesurments and all was the same as old rotor exept the magnet power it was really febble in desperation i drilled out the magnet what was 6mmx2mm after a lot of searching i found a very strong fridge magnet 6mmx5mm i drilled the backerlit deeper to 5.5mm put in chemical metal and pushed magnet in flush checking the pull on the magnet was the same field as my original the magnet was the wrong way in on the new one started perfect 800miles all is exellent hope this may help others cheers

Does the new rotor have 5+ ohms across the slip rings?

Glenn

 

[malc]

yes it does 5.2ohm charges well 13.4v at tickover 14.4v at 2700rpm its nice to see where im going at night makes a change cheers

 

[XSLeo]

The people that have done this have reported that here was no clearance problems.
I think that might be part of the problem. The magnets in the rotor may be strong enough, just to far away from the pick ups. Adddin the magnet moves the magnet closer as well as being stronger.
Leo

 

[650Dave]

The people that have done this have reported that here was no clearance problems.

I have done it recently with a Radio Shack rare earth magnet, and there were no clearance problems. Those magnets are really small. But strong.

 

[hmusket]

Congratulations on your fix Malc, and thanks for sharing another way to get something done.