Persistent flat spot off idle

That part number, 21148-1020 fits all KZ1000 and 1100 engine from 1981 to 2005.
I am glad your headed in the right direction. When I was trying to figure mine out I think I spent about $2000.00 over the years I was trouble shooting it. Different carbs, jets, exhaust systems, cams I even bought and fixed up a stock head just to make sure the head porting was not my problem, it wasn't, Unfortunately I had never had the engine running in stock form, got it as a basket case and I highly modded it so I did not have a base line, that was my underlying problem. I usually do one performance mod at a time get that dialed in them move onto the next. I didn't do that on this one so I ended up with a very long and expensive solution.
The up side is I learned a LOT about tuning these big fours.

This interesting . I have fought some of these issues and i think im good now. But im curios , I had taken off my advancer to give it a look.
I didn't grease it but it looked fine to me. From what im gathering its hard or impossible to tell if it not functioning correctly?
Dont mean to highjack the thread but whats the best way to check this thing? I dont want to just blindly buy a new one when mine is fine.
And when yall say grease it. are we talking adding a dab to the pivot points?

Grease the rotor spindle. Test it with a timing light. At idle it should be on the F mark and gradually move over to the line next to the pin up to 3500 RPM. If it jumps around, the springs are bad. I bought a used good one from another model just for the springs. BIG difference.
Steve

The springs are what go bad on these and they will look fine. The test above is a good one, didn't work for me though. I bought 3 used ones that looked brand new and all tested with the timing light trick. All tested fine but the springs were still bad. I even did the old school trick of cutting a coil off the spring to tighten it up, worked in the past for me but no joy there either.
No grease just a very light oil on the shaft and pivot pins.