ATU - will a KZ650 Twin ignition advance unit fit a KZ440 Ltd

Hi All,

I have a KZ440 Ltd that i purchased as a non runner due to the ATU being mangled by the previous owner - the weight lugs that interface with the advance unit had been broken off, so the magnet just spun and done nothing.

I can see that a KZ650 twin ATU pritty much looks the same - I was wondering if this would work on the 440, as actual ATUs for 440s are like Rocking Horse excrement

I did try getting an old 350 unit and took the weights off that to put on the body of the 440 unit but they are sticking and not swinging freely (ooher misses!)

Any ideas or info would be a great help

Simon

The bigger twin is a 750 (not 650) before you worry about whether or not it will fit I would look at the manuals for both and compare the advance curves

However, be careful. Although these advance mechanisms look identical, they don't have the same ignition advance characteristics. The weights differ from one model to another. I'm not sure, but I think the cams do too (minimum advance at idle).

Bloobaba wrote:

However, be careful. Although these advance mechanisms look identical, they don't have the same ignition advance characteristics. The weights differ from one model to another. I'm not sure, but I think the cams do too (minimum advance at idle).

Also the spring rates differ - back in the day tuners messed with weights and springs to customise advance curves