No eBay APP ID and/or Cert ID defined in Kunena configurationFor engine mod tips and the best combinations, I would look up similar replies on this site from Larry Cavanaugh.
kzrider.com/forum/profile/25825-larryc
Here is another Cavanaugh reference:https://www.kz-1000.net/post/130285291257/faq-about-kz900-kz1000-engines
If you upgrade to a 1075 kit, most folks go with the 10.25:1 compression as opposed to the stock-ish 9:1. In this case, I think higher compressor allows for/requires performance cams. But Larry generally seemed to recommend modest cams along with good porting (his specialty). He seemed to be a fan of the 118 grind.
kzrider.com/forum/2-engine/253470-there-...am-on-a-kz900#253563
As for sticking with the 26mm carbs, there is no reason they would not work. However, you might be giving up some power at the top of the RPM range as a smaller carb body can only pass so much air volume. On the other hand, smaller carbs are said to have better throttle response in the middle range than larger ones.
The place where you might run into trouble with the VM26 is if you went with a really big gnarly cam. As the cam gets more aggressive, generally the optimal power range moves to a higher RPM. A gnarly cam paired with small carbs could mean that as the RPMs climb, just when the cams start really working they get choked by the smaller carbs. So that would be bad. But it doesn't sound like that's the direction you're going.
A modest upgrade might be to find a set of VM28s from a 79/80 KZ1000. These have accelerator pumps and are not in really high demand, although prices for all of this stuff have gone up a lot recently. You might have to watch Ebay for a while before you find a good set at a reasonable price.
This is what they look like, but don't buy these because they are gross and overpriced.
Or send a note to Nessism and see if he has a set. He's been rebuilding them for fun.
kzrider.com/forum/profile/14026-nessism
