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Discussion Starter · #1 ·
Hi all I have a Kawasaki zx10 89 with an aftermarket exhaust. I'm wondering if I need to have it dynojetted as I heard that if it pops a lot it means it's not getting enough fuel and running lean and hot.
Any input from anyone greatly appreciated as always :)
Thanx all happy riding.
 

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popping on accel to decel?
 

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All bikes have been set lean from the factory since the late 70's. Call Dynojet and get one of their jet kits. You'll have smoother idle, better acceleration, less popping and flat spots in the powerband and if you're lucky and don't go whole hog, your fuel mileage will only decrease by a small amount.
 

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Discussion Starter · #5 ·
Yeah that's the plan Hammerhead and thanx. I just wondered if what I was told was correct as it doesn't make sense. Surely the popping is from unburnt fuel from being too rich?
 

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Quinton Phuckin Tarantino
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Yeah that's the plan Hammerhead and thanx. I just wondered if what I was told was correct as it doesn't make sense. Surely the popping is from unburnt fuel from being too rich?
Just because there is unburnt fuel doesn't mean that the mixture is rich . It just means that the cumbustion is incomplete . Without a proper a/f ratio the fuel won't burn right , rich or lean .
 

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Stock ZX-14s have a decel pop at 3500 rpm trailing throttle caused by the ECU leaning the fuel mixture out to pass an emissions test. Not all popping is caused by rich mixtures.
 

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Quinton Phuckin Tarantino
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Idle and decel
Right so still none the wiser
Generally poping at idle means one of two things ,either you have a plugged jet/passage or a burnt valve . Using a dynojet kit or something similar generally won't fix an idle problem. Do a compression test to see if the valve is burnt then pull the carbs apart and see if one of your pilot jets is clogged .
 

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zx 11 problems?

Ladies and Gentlemen, I hope these are not stupid questions but I am unclear on the answers. I have a 93 ZX11 D1 that is 0.040 over sized (done about 2 years ago). Since then I have been noticing that the bike is running a little hotter than it used to, slight popping from the exhaust on decal, idle hunts about 2-300 rpm and light surging at cruising speeds at 4-5k rpm. Compression is good, plugs look good, valves are adjusted and coolant is full. I am thinking it is running a little on the lean side. Bike pulls fairly hard but I think there should have a bit more.

The carb setup, idle screw is 1 ½, jets 1-4 are 162 2-3 are 160 and needles are N96X on all 4.

I have been reading that 2 turns seems to be the norm if I make it 2 turn will it make it richer or leaner?

If I want to go richer on the jets what number should I be putting in, a higher or lower number?

Last year a slide diaphragm failed, so I change them all from a set of carbs that I have from a 99 ZX11. While I was transferring the needles from my slides (aluminum) to the 99 slides (plastic), I noticed that there was a 0.020 washer/shim under the head of the needle. Not sure if this was factory or added after. Should this washer s be with the plastic slides? If so by re adding them would this make it run richer?

Sorry for all these questions, but I just would like them clarified and may be help out someone else too.
Thanks for any help with this.
 

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these are the jet sizes for the 99 1-4 are 160 needles are N96K, and 2-3 are 158 and needles are N5AK.

Can I just use these needles and jets on my carbs?

Cheers
 

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Did the performance change when you changed the diaphrams?

Turning out the idle screw will richen the idle circuit. Fully closed = no fuel. as you open the idle screw more gas is let into the idle circuit. With respect to the jets, the higher the number the bigger the jets. big jets let in more fuel than small jets.

The washer under the needles richen up the mid-range circuit. Put the washers under all four needles.

Hope this helps. The idle circuit gives up at about 3500 rpm, and the needles take over at that point to about 7/8k rpm, then the main jets. Main jet sizing does effect mid-range and low-range performance. The normal process is getting the main jets sorted first, then needles, then idle screw.
 

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Thanks for the clearifaction, the performance did not seem to change much. Are the washers stock or an addon? Should I use the the needles out of the 99 carb setup?
1&4 160 N96K
2&3 158 N5AK

or stick with mine

1&4 162 N96X
2&3 160 N96X

Thanks again

Cheers
 

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Ladies and Gentlemen, I hope these are not stupid questions but I am unclear on the answers. I have a 93 ZX11 D1 that is 0.040 over sized (done about 2 years ago). Since then I have been noticing that the bike is running a little hotter than it used to, slight popping from the exhaust on decal, idle hunts about 2-300 rpm and light surging at cruising speeds at 4-5k rpm. Compression is good, plugs look good, valves are adjusted and coolant is full. I am thinking it is running a little on the lean side. Bike pulls fairly hard but I think there should have a bit more.

The carb setup, idle screw is 1 ½, jets 1-4 are 162 2-3 are 160 and needles are N96X on all 4.

I have been reading that 2 turns seems to be the norm if I make it 2 turn will it make it richer or leaner?

If I want to go richer on the jets what number should I be putting in, a higher or lower number?

Last year a slide diaphragm failed, so I change them all from a set of carbs that I have from a 99 ZX11. While I was transferring the needles from my slides (aluminum) to the 99 slides (plastic), I noticed that there was a 0.020 washer/shim under the head of the needle. Not sure if this was factory or added after. Should this washer s be with the plastic slides? If so by re adding them would this make it run richer?

Sorry for all these questions, but I just would like them clarified and may be help out someone else too.
Thanks for any help with this.
I'd check petcock filter and fuel pump pressure.
 

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thanks Ozzy, I did not know there was a filter in the pet cock. What should the fuel pressure be at?

Thanks again everyone.

Cheers
 
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