Z1 KZ timing advancer question

This is my first post. Love this site. You guys have been a great help.
I am working on my 74 Z1-A 900/1075-29 smoothbores.
1 and 4 are not running as clean as 2 and 3. I just put in new dyna coils and added WG's relay setup to the ignition system. Carbs are in great shape and compresion is 145 all cylinders.
So I am going to replace my old dyna 3 with a dyna s. Z1 Enterprizes mentions a different rotor for the early advancer ( 5 btdc ) and the later advancer (20 btdc ).
Does anyone know which advancer would work the best in my engine. I have the early one in it now but also have the later one on a kz parts bike.

Which one to use ?
Thanks, Todd.

tworevs wrote:

This is my first post. Love this site. You guys have been a great help.
I am working on my 74 Z1-A 900/1075-29 smoothbores.
1 and 4 are not running as clean as 2 and 3. I just put in new dyna coils and added WG's relay setup to the ignition system. Carbs are in great shape and compresion is 145 all cylinders.
So I am going to replace my old dyna 3 with a dyna s. Z1 Enterprizes mentions a different rotor for the early advancer ( 5 btdc ) and the later advancer (20 btdc ).
Does anyone know which advancer would work the best in my engine. I have the early one in it now but also have the later one on a kz parts bike.

Which one to use ?
Thanks, Todd.

First off, welcome! You'll find lots of differing opinions on what to do with your ride (which looks really sharp by the way!). The only things we do agree on are: 'Old Kawi's rock', and 'ride that bike!'

My personal opinion is to keep the one that came with the bike; not that I'm an original parts nut or anything. It may just work like it was supposed to. Just make sure its in good shape. Your Dyna S is a 'set and forget' setup, but you can use a timing light to check your advancer is working properly.

Were the 1&4 cylinders having trouble before the mods or after? Check the voltages at both coils (just to make sure you did both sides properly) and double check all of your grounds. I'm assuming that the wires, caps and plugs are new too. If all else fails, swap the coils around see if the problem moves. If it does, then it could be a coil issue, if not, there may be an issue with the Dyna S (or the wiring to/from it).

hope this helps...and I'm not a real mechanic, I just play one in my garage!

the 5/40 advancer found in the 73 and early 74 Z1's gives a very rough idle - esp. when the engines have a few miles on them. Generally I prefer the 20/40 advancer found in the later Z1's and early KZ's.

Tried the 20/40 today and the engine definately idled better but the electric starter did not like it when hot. Probably due to the 1075 kit and 145 compresion. So I ended up putting the 5/40 back in. My 1-4 problem may be cured now as I found the 1-4 timing a tick retarted and gas level in 1-4 carbs 2 mm higher than 2-3.

Thanks for your help, Todd.

You probably want to retard the ignition a little - I would suggest around 36-37 degrees fully advanced (instead of 40 degrees).

The higher compression coupled with the crappy fuel these days... this should also reduce/eliminate the detonation (pinging) rolling on through the mid-range.