Timing light for kz750

Ok, on the 550, which I think uses the same rotor as the 750-4, the OD of the rotor stem, where the rubber stops touch the rotor, is 20.5mm.

If yours is less, then that may be the problem. But we will need to know if a 750-4 (KZ750F1) uses the same rotor as my 550. We can't use part numbers, since it is all part of the advancer assembly and they have different part numbers due to different advance curves.

We will need someone to confirm the rotor diameter on a stock version of your advancer. The other option would be to build up a little material on the rotor where the rubber stops touch. I don't know if epoxy would be good or what else you might use. If the epoxy fell off, all that would happen is the idle would get rougher and slower.

The other option is to build up material on teh full-advance tabs. But you have to be sure there is no way for the material to come off. If it comes off, the motor will knock and possibly break apart under heavy load.

Sweet, thanks loudhvx. I've been busy with work and I'll check that out tomorrow. Thanks for checking that out for me.

loudhvx wrote: Ok, on the 550, which I think uses the same rotor as the 750-4, the OD of the rotor stem, where the rubber stops touch the rotor, is 20.5mm.

If yours is less, then that may be the problem. But we will need to know if a 750-4 (KZ750F1) uses the same rotor as my 550. We can't use part numbers, since it is all part of the advancer assembly and they have different part numbers due to different advance curves.

We will need someone to confirm the rotor diameter on a stock version of your advancer. The other option would be to build up a little material on the rotor where the rubber stops touch. I don't know if epoxy would be good or what else you might use. If the epoxy fell off, all that would happen is the idle would get rougher and slower.

The other option is to build up material on teh full-advance tabs. But you have to be sure there is no way for the material to come off. If it comes off, the motor will knock and possibly break apart under heavy load.

Sorry for the delay, I've been a little busy this past week. Anyways, I just took the advance off and took some closer pics. First of all I have the dyna rotor on it. I do have the original rotor. I'll go dig for it and get a measurement.

Okay, so the OD of the original rotor is just like you said,20.50. The od of the dyna rotor is 20.40. Now what? By the way, good call loudhvx. Maybe I can call dyna and see if they have any other sizes of rotors.

Hmm. It's hard to believe that .1mm can make that much difference.

You could swap the rotors and see if the stock rotor will make the marks line up. You can check without running the engine. Just mount it up, rotate the motor until the F mark lines up, then rotate the advancer rotor (making sure the engine doesn't move) until the double lines line up.