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On a 98 zx7 carb bank i have 4 mains @ 136 and 4 [email protected] 35 does that sound right? The bike has a full hindle exhaust and im doind the float bowl mod. floats are at 13mm Im at 2 1/2 turns out
Stock mains are 170,180,180,170. Factory Pro mains come in sizes 168, 172,172,168 and 178,182,182,178. Usually the outer two banks are smaller than the inner two. If I'm not mistaken, those 136 mains are a Dynojet brand jet kit...someone should be along shortly to offer more information regarding the jet sizes.

As far as the float bowl mod, once it's done, you may have to do some slight tweaking/tuning with the float heights and pilot screws to get it properly tuned.

Good luck and ride safe
 

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t IS a Dynojet kit. Mine has 136 and 138s.
 

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The extra holes in the slides actually don't do anything. Why DJ keeps suggesting that procedure is beyond me.

Josh
 

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DJ doesn't suggest extra holes, just larger ones. Its factory pro that says to drill a second set.

And the idea is that it slightly improves response.
 

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my FP never suggested a second set. not sure where you got that from. but you are right about the large instead of additional holes for the dj kit. just checked the directions. And they state that it may make things worse down low but will increase response above 4k.
 

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Discussion Starter · #8 ·
Thank you for your input, i will have to look at the slides when i get home later. The way the carbs are set up is the way the previous owner had it, i just cleaned them up. as to the float bowl mod. . Does 1-2 and 3-4 get connected. I just have them plugged off right now, its is a little unclear. And do the 2 vent lines -1 big and 1small- going to the air box get plugged or connected back to the air box
 

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Discussion Starter · #9 ·
The bike was sitting for 2 years, the guy I got it from set it just quit on him. I paid $400 for it changed the plugs, cleaned the carbs and a new battery and it started right up
 

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Discussion Starter · #10 ·
Does anyone have a carb sync tool they could lend me for a few hours, $100 for something im going to use 1time, i just cant do it.
 

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You can make your own carb synch tool for around $10. Google "diy carb synchronizer tool". It's nice to have one around because if you do any playing around with the carbs, you'll need it again.

Be aware that the 7 only comes with 3 adapters for the take off points to do the synch, the fourth one on #2 has a block off bolt. So you'll need to source a fourth one or switch one back and forth while having the carbs hooked up two at a time instead of all four at once.
 

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Does anyone have a carb sync tool they could lend me for a few hours, $100 for something im going to use 1time, i just cant do it.
They aren't something you will use just one time.

I use mine a bunch.
 

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For the float mod, the two little lines that come from the nipples right below the carbs get plugged. The larger line that t's from the top of the carbs gets connected with a short piece of tubing to the smaller line that originally came from the valve and went into the front of the airbox, and then goes back into the airbox again. The larger hole remaining on the right front of the airbox gets plugged. Hope that helped.
 

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DJ doesn't suggest extra holes, just larger ones. Its factory pro that says to drill a second set.

And the idea is that it slightly improves response.
my FP never suggested a second set. not sure where you got that from.
^ Correct.

Factory Pro makes a drop-in kit, no drilling. Dyno Jet is the one that suggests that an auxiliary hole be drilled the slides right in their instruction sheet. I know because I dealt with a few of their kits on 7Rs before, plus I've corresponded with them via email to clear up some of the details.
 

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Discussion Starter · #15 ·
How good is the home made sync tool? I picked up a new stock air filter, fuel filter, and oil filter today. What is everyones thoughts on chains and sprockets. Ohh there is no extra hole in the carb slides
 

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How good a home made synch tool is will depend on how good you make it ;)
It isn't difficult. You aren't going to be measuring the actual amount of vacuum, you are just measuring the relative amount, making the carbs all match. Use a thick, easy to see fluid that won't hurt the engine if the synch is off by so much that some gets sucked into the motor. I think you can even install some restrictors in the lines to minimuze the jump if you really want.
 

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jets

iv just spent 6 months and at last i have mine running perfect. yes you have dj jet sizes... to get mine to run properly i ended up with 132 mains on all four. screws out 2.5 turns out from fully in and airbox mod but the thing that made the best change was moving the floats from 13.5mm to 15.5 mm. it was fluffy and spluttery until i moved to 15.5mm..:clap
 

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Discussion Starter · #18 ·
Some helpful info I found today

I didn't know it was recommended to do the flow bowl mod with the Dynajet stage 1 kit, I have the carbs off and going through them again I keep getting junk/dirt in them. I also read that the fuel pump gets dirt or rust in it and can push it into the carbs. So I will be replacing the pump also, I only got to ride around the block last year...I'm hoping to get a little more in this year

Before jetting a ZX7R be aware that Kawasaki uses ram air induction (pressurized airbox) to deliver air and equalize pressure needed to draw fuel through the intake. Coupled with the vacuum system is a fresh air induction system that allows air into the exhaust system giving you that fun popping during heavy decceleration. These factors, of which I don't claim to understand fully, result in the factory main jets to be larger than most aftermarket kits. For example; on my 2003 7R I had 170 and 180 main jets as stock equipment, and the DynoJet Stage 1 kit had DJ-136 and DJ-138 mains (the numbers are not fully comparable in sizing).

Installing an aftermarket kit including main jets, slide springs, and needles without changing anything else will cause your bike to starve for proper fuel delivery. So do the following:

1) Remove the screen support bracket and mirrors 2) Remove the fuel tank 3) Remove the airbox (taking off the ram air rubber duct joints will make removal and installation easier)

When removing the airbox notice that the two tubes at the front are hooked up to two silver things as in the attached picture (taken from http://homepage.ntlworld.com/webzxr/.../ventbowl.html ).

4) Take out those two silver things!!! 5) The silver thing at the front of the bike has the carburetor bowl vent tubes hooked up to in. It is CRUCIAL that you route that hose from the carb DIRECTLY into the airbox. I used the existing port on the left side of the airbox cover.

6) Take the two big tube that come out of the valve cover and connect them together. 7) Plug the two remaining little vacuum tubes (one on the right side of the bike near the front, and the other on the left by the carb body).

8) You will now need to seal the remaining hole in the airbox cover with a good seal of some kind. 9) Install the jet kit per the instructions. 10) Button it all back up and test it out.

You should now have a good baseline to work with and changes should be predictable and make sense. Without making the above modifications first, you will be going back and forth wondering what the hell is going on. I didn't come up with this stuff myself of course, I was lucky to find the following webpage that really helped out; http://homepage.ntlworld.com/webzxr/.../ventbowl.html

DynoJet was also helpful in providing good instructions in their kit that basically hinted at what needed to be done, but due to the specific nature of the problem other sources of information was needed.

Good luck.
 

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How good is the home made sync tool? I picked up a new stock air filter, fuel filter, and oil filter today. What is everyones thoughts on chains and sprockets. Ohh there is no extra hole in the carb slides
I made one a few years ago by attaching clear hose to a wooden yardstick. After trying various fluid viscosities I settled on Sta-bil fuel stabilizer as it seemed to give the best readings and no worries if a little gets sucked in. Last year I bought a Carbtune but am now wishing I hadn't dropped the coin. They read so close to one another... The only advantage with the Carbtune is you can do all 4 carbs at once.
 
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