ER5 (electrex) rotor on z1000j

Hi there. I need to replace my rotor (flywheel) in my ‘81 kz1000ltd with J engine. I saw in the electrex page that an ER5 rotor would work on the Kz, see link:
www.electrexworld.co.uk/acatalog/RO3.html

I got it, and when comparing with the original rotor, it’s a tad bigger, like 1cm wider diameter.

has anybody used such rotor before?

 

I guess given that it is sold as a replacement for the "J" motor you would like to think it would be ok. Is the difference in diameter external or internal ? if internal it will have a bigger air gap to the stator but you would like to think that has been accounted for in the strength of the magnets used ?

Wookie, good to read you again. It fits great in the crank; it’s just the distance to the engine cover that worries
me.
as the engine is nos yet assembled I cannot try it. Thank you!

Maybe they have improved the tolerances since, but I had a hell of a time installing a Electrex RO5 rotor.  Then the magnet developed a crack.

That was it...sent it back.  Good riddance!

I will stick with stock OEM Genuine Kawasaki generator rotors.  They fit, period.

Have two stashed.  One was spoken for awhile back.