Idle and exhaust pops

Hello,

I have a kz1000 ltd b2 1978.
Since i have it i never get a correct idle.

Each carb came with a main jet at 110 and a pilot jet at 20.
Wrong idle but no pops or really minimals.

I buy 4 new carb kits and new manifolds because the old ones was totaly dead.

I finally have a correct idle with a main jet at 105 and a pilot jet at 15.
But i have a lot of pops...

Today i try a main jet at 110 and a pilot jet at 17.
It's not good...

I have stock air box. 1 mix screw on the bottom of each carb at 1 + 1/8 turns out.


For the moment I think i have to go back with a main jet at 105 and a pilot jet at 15 :
But why all those pops ?????

Why this carbs came with 110 main jet and 20 pilot jet?
The parts look oem kawasaki parts...


Cheers
Fox

Carbs synced?
Steve

If it was my bike and since it has the stock air box I would put the stock jet needle (5CN7); needle jet (AO-3); and pilot jet (A15) in it and see how it runs. I figure the bike ran well when it was new and had those parts so it should run well with them now (see link below). Ed

www.powersportswarehouse.com/p/Kawasaki#...00-B2-1978/070061C-7

- Not actually syncro.

- the new main jets i have is at 105.
Specs are at 102.5
Do you think it's important ?

Regards

At least bench sync them. Valves adjusted?
Steve

@Steve
Do you think scync can reduce exhauts pops?
Pops are at the end of the exhausts
(no backfire or pops from the air box)

Fox wrote: - Not actually syncro.

- the new main jets i have is at 105.
Specs are at 102.5
Do you think it's important ?

Regards

Yes. Since you are trying to isolate the problem causing the pops I believe it would be best to eliminate as many variables as possible. Putting the jetting back to stock will eliminate the possibility that the non-stock jetting is causing the problem. In fact, it may eliminate the problem, but even if it doesn't you will know for sure the jetting is not causing the problem so you won't spend additional time and resources trying different jetting combinations to fix the problem. Ed

Fox wrote: @Steve
Do you think scync can reduce exhauts pops?
Pops are at the end of the exhausts
(no backfire or pops from the air box)

If they that far out it will pop. Valves adjusted?
Steve

Yes valves are under specs

This is my B2, there are no smog attachments and a non standard exhaust i also have a stock air box, the jets had been played with but i now have a 107.5 main, a 20 pilot, needle 5cn7 on groove 3, pilot screws 1 & 1/4 turns out, runs perfectly, when i got it it had 117.5 main, 25 pilot, needle 5cn7 on groove 4, and it ran like a pig, if you aftermarket exhaust with some baffling, go to the same as mine you wont be far out 102.5 and 105 jets run too weak,.

Hello,

beautifull bike, congrats for the job done.
So clean ! would like to see inside

Is your exhaust 4 in 1 ?

Best
Fox

Yes, stainless 4into1 with a harris road baffle.