kz 1000j jetting

hello, I would appreciate any info on jetting a 82 kz 1000j that has a (Vance and Hines 4 into 1),and a (K & N) in airbox filter. I just had valves done, and a 1100 cylinder block bored .30 over, Stock idle jet is 37.5, main jet is 127, and the needles has no grooves to raise or lower. It starts up with idle jets at 35, but stutters up to 2500 rpm, played with fuel mixture from 1 1/4 to 2 1/2. runs great from 2500 to 5000, can't rev any higher til I have a few more miles on engine. Any ideas will help. I am using the stock carb's 34 mm mikuni's. Thanks

Post edited by: KZrider82, at: 2006/04/06 17:19

Post edited by: kzrider82, at: 2006/04/06 20:30

ive got about the same setup and run 135.7 in mine

thank you for feedback, what do you have for the idle jets?

I suspect you won't appreciate this fella's help so much when you actually try and buy the #135.7 main jets. You ain't on main jet where the bike is stuttering. You are on jet needle... Suggest #140 mains, #40 pilots and use a couple of Mikuni shims on each jet needle.

sounds great. where do you get shims for the needles? ,and when I run the 37.5 jets it runs rich and won't start too well, so I've been running 35 jets so it will at least start. would you still run 40 jets in it.

It honestly sounds like your bike need some work. I test BS34 carbs on a KZ900 and with your set up can easily run #40 pilot jets. If you need to lean the idle mixture so much that you are using smaller than stock pilot jets with an aftermarket set of pipes and K&N drop in filter, I would read the Filebase article on coil powering to see if you are possibly having a weak spark which means poor combustion.

As far as where to buy shims, contact www.z1enterprises.com and tell the owner, Jeff, that you need the larger opening type Mikuni needle shims. You could use shims from a hardware but they tend not to be as accurate as far as thickness goes.

I agree, I do have a dyna 2000 ign.,dyna coils,and a fresh battery,the spark is big and blue,and the timing is perfect, so you can imagine my frustration. I was hoping someone would suggest the starter plungers could be leaking. I had that thought, but didn't really want to take them all apart if no one has ever heard of them going bad.

Post edited by: kzrider82, at: 2006/04/07 09:35