Main Jet Size Question

I am trying to rebuild the carbs on my KZ650 B2. The main jets are too corroded to read the size. The new kits include jets that are , 90, 97.5, 102, & 102.5. The bike is stock with stock a/f and box. Has a "4 into 1" pipe. What main jet should I put in?
Thanks

Lordy... I could look at buykawaski.com and try and figure out which carburetor assembly came with your bike (they give ranges for the engine numbers next to the part number) or you could do it yourself.

Typically, the sets with small #50 tubby jets that cover the pilot jets use the #90 or #92.5 main jets.

I really can't imagine why they put in #102 and #102.5 main jets as these are essentially the same size. It won't hurt anything to use those jets in any case. You are really running on main jet ONLY when the throttle is wide open. The slightly larger main jets (#102.5) works well in all the VM24 carbs as the #90s are a bit on the puny side.

Well, I tried buykawasaki.com. According to the parts sheets there, my carbs are #16001-1084. (I am assuming the carb part# are based on the seriel # ranges that listed as F/N *******). They are not listed by any of the jets, just says spec code #4. Where do I find that?

How about cleaning the jets with a wire wheel Dremel bit or wire brush? Would that help?

Hi, I also have a KZ650 B2. I just went through my carbs, the main jets are 102.5 and the pilot jets are 15.
I believe that this engine is flat stock, I bought it out of Kansas, and supposidly it had been in a minor collision (is any collision minor??) which took out the front end with no damage to the engine (it hasn't blown up yet, so must be true). Supposidly has 5000 miles on the engine.
Hope this helps.

Thanks for the info guys. I went with the 102.5s. Too rich won't damage anything, but too lean is not too good. I can lean later if needed.

Since main jets mainly are in use during wide open throttle, the effect will be bogging if you are too rich. I bet you are not. I have NEVER heard of anyone fouling a plug because they were running wide open with too large main jets... performance (acceleration) will suffer is the only effect.