Bike keeps dying, high idle, help?83 kz650

I will have to check again. I might have seen it wrong. But I thought it sai 107...coulda been 102 though. Any idea what those little needles are beside the vacuum ports?

Not sure what needles you're talking about. Do you have a picture of them?

Not taken out but I have a lot of it in the carb. It right beside all 4 vacuum ports on the side that mounts to the motor. They have a little spring I think it's called an air needle. Here's a video.


He start messing with it at 7:00min in. I didn't count my turns out like he did so I feel like it might have something to do with why its not running 100% just yet.

There should be a pic attached. It's the two small screws beside the two vacuum ports (there are two more on the other two carbs) and if you unscrew it its a very small long skinny needle.

Ah ok I believe you're talking about the mixture screws. The standard setting is 2 and a half turns out. Lightly seat the screw ( don't screw it in until its really tight) and count 2 1/2 turns out. It may not be exactly right but it should get you in the ballpark

Ok, thanks so much. I will do that when I get home.

I think the 83 carb stuff is the same as the 82 KZ650-CSR (H2). With the stock airbox & stock exhaust system, you can probably go with larger main jets than stock. From the 81-82 manual:

Main jets = 107.5R .... (Canadian models are 110R).
Jet needles = 4030 .... (Canadian models are the same as the F4 = 4031-4)

Except for the main jets & jet needles, everything else is the same as the 83 F4.
(see the 1983 Supplement page - F4 carburetor spec table - posted on pg 2 of this topic).

Jet needle stuff.
The "4" in the jet needle number for the F4 (4031-4) is the groove number for clipping the jet needles.
The groove numbers are counted from the top (#5 is the lowest groove).
The 83 H3 may not have grooves on the jet needles, since there is no groove number indicated.

Air mixture screws (pilot air screws) There isn't a factory setting listed for the air mixture screws. In general a starting point is 2 to 2.5 turns out from the seated position. Since the plugs are missing, someone may have already fiddled with yours. But before messing with them, while counting the number of turns, very gently turn in the screws until they just seat - note the number of turns. Do not turn them in hard - the tips can break off & that would be a bummer.

^^^ this was extremely helpful and informative. I can not thank you guys enough for how muh you have helped me. I will tinker with it when I get home. I feel so close to having this bike on the road.

Ok guys, grand news. It ran tonight in cold weather with out the choke it's still running a little rough could probably use a tune up. My last complaint and thing I need help with (for now lol) is when. I rev the idle falls SUPER slow. What could that be?

If not already done, could adjust the throttle stop screw to increase idle speed.

Good Fortune!

Yea sir, I've got it idling at 1500ish rpms. It's idling fine (ish). It's just when I rev it, it takes so long for it to wind down. Kinda like its sticking and slowly releasing.

Did you synchronize the carbs? It should be pretty easy to do. You'll need a synchronizer set of some sort.

Also make sure when you roll on the throttle it immediately snaps back. If not your throttle cable could be hung up somewhere