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Discussion Starter #1
As some of you may recall I had that obnoxious thread about ZOmG GuYz CheX MY New ExhAUst ....

k so now I'm at the fun part:

I've started jetting the carbs, and I changed out the main jets and the bike didn't want to turn on, but it finally picked up and two things happened:

+ Killing the choke made it turn off once.
+ Hitting the throttle made it turn off twice.

Restarted and after it warmed up again it was ok - I had a flat spot between 3 and 4 so I was going to adjust the float height in the morning. Just like the instructions said no big deal.

I just went downstairs and it's not turning on at all. Just turns over and nothing.

I was going to give you a call Art but didn't know if it was too late - any ideas at all?

Thanks.
 

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Discussion Starter #3
Re: Jetting carb problem (please kill me.)

I was told - and affirmed by research - that the carbs had to be jetted when you installed the exhaust for other reasons I don't even know.
 

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Re: Jetting carb problem (please kill me.)

Bang! Your dead.

FOG
 

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Re: Jetting carb problem (please kill me.)

Do the needles have adjustments on them (a clip that goes in little grooves on the jet)? Sounds like you're running way way way too rich. Too rich means the clip is too low (close to the pointed end). Good news: You're ready for a turbo or some nitrous. Bad news: FOG was right when he said not to do it.

The flat spot can be adjusted out with the pilot screws (do a little searching, it should turn up on the site), but you're going to have to do something with those needles first.

Also, did you sync after swapping the needles? I'm assuming that would cause problems, too.

Big picture lesson: jetting is required in instances where adding an exhaust or intake system would put the fuel requirements outside the realm of the possible adjustment of the stock carburetors. It sounds like, as a general rule that may not apply to all (like Charles or Art's equipment and methods of adjustment), the EX500 is a bike on which you can install an exhaust and everything is still within the realm of adjustment. The bike might work with jets, but the jets they gave you seem way too rich to me.

This is all assuming that everything is back together the way it's supposed to be. As for the floats, unless you did something do them I don't know why they'd be messed up now when they weren't before.
 

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Re: Jetting carb problem (please kill me.)

Simple....go back to stock (134 main, 25 pilot, OEM needle) and start again.

THIS TIME READ THE INSTRUCTIONS IN THE KIT FIRST!
 

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Discussion Starter #8
Re: Jetting carb problem (please kill me.)

Thanks for slapping some sense into me guys :)

I thought I kept up with the instructions - but I didn't replace the needles....or the pilots... ROFL - OK better get on that - thanks again.
 

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Re: Jetting carb problem (please kill me.)

Err, on my 91 the stock main jet is a #130. Might be different for later years.

Clips are on needles, not jets.

If you just replaced the exhaust, and have an otherwise stock intake (no holes, either stock filter or K&N) you should have gone up to the next size main, and left the needles alone.

Float height does not effect mid-range flat spots. Needle position does. Float height can help with an off-idle stumble, but it's only a quick fix. What you need in that case is to adjust the pilot screw, or in the worst case install a larger pilot jet.

Charles.
 

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Discussion Starter #11
its workinG!!! ?laidGUE8T,ASJGKLSDJGK!!

;D

oK - let's just calm down here - boy was I flying all over the road. *adjusts tie*

OK I didn't replace the needles the first time (cuz I'm stoopid :) ) - Just the main jets.

So I put the clips on the 3rd needle deal. Shot it in. And now I took it for a spin and I made the following observations.

- This is really loud.
- I feel like I have much less control of the bike
- The sound of my bike is very loud.
- When I would "floor it" - I would usualyl get a big boost in first and change gears around 6-7k when I felt - I was losing the torque - Now I feel I need to get to 4th gear in a few seconds
- This feels like someone elses bike, that is very loud.
- Please remind me to not be a squid in the next weeks.

But from a mechanical standpoint - does it sound normal / ok to have only done what I did and feel like the bike is performing fine? (I'm sorry for all these 4th grade posts, I've learned everything I know about carbs this weekend, and as you can see I wasn't as calm and collected it about it. )
 

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Shoot... it's cool that your willing to learn and DO.
Why that reminds me of the first Rochester 4bbl I rebuilt.
writer leans back & rubs chin

It was on a mid '60s 327 Chevy...
writer begins a dream sequence, camera blurs & fades....
 

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You shouldn't need to change the needles. Just one size up on the main jet. Only ever change one thing at a time when working on carbs. Each change interacts with each other change you make, and you'll have a hard time troubleshooting if you change everything at once.

To reduce the noise, you may be able to remove the baffle and pack fiberglass around it. You may also be able to get a quieter baffle, depending on the manufacturer.

Charles.
 

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Discussion Starter #14
Well when I just put on the bigger jets it was flooding the engine and it wouldn't start at all. Then I took out the stock needles and noticed they couldn't be adjusted and were way diff. in size than the 3rd notch on the Factory Pro one. I still feel like my take off is not stellar - but I can't tell. I think at this point I'm gonna give in and throw it on the Dyno or so.

I secretly like how loud it is ;D
 

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Then your main jet was way too big. Still is way too big.

Adding an exhaust (and not messing with the airbox or anything else) is a very minor mod. It will make the bike run only *SLIGHTLY* leaner. You can get away with not rejetting at all, but a good rule of thumb is ONE main jet size. So if your stock mains are 130's, you'd go to 132.5's. (the next size up). Also remember that Dynojet and Factory Pro jet numbering does not match stock Kawasaki numbering.

Now, I'm guessing that the only reason your bike is running with this setup is because you have the needle adjusted WAY down.

With the slider all the way up, the needle should be COMPLETELY up out of the orifice in the venturi. You should be able to see the tip. This allows maximum flow out of the main jet at wide open throttle.

When the slider is all the way up, if the needle is still down inside that orifice, and that's the only way the bike will start and run, then your main jet is too large.

From the starting point of the needle being fully out of the orifice when the slider is at maximum lift, you may raise the needle UP (and only up) to tune out midrange flat spots (providing more fuel earlier in the lift). Max fuel at full throttle remains the same.

Charles.
 

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Discussion Starter #16
Thanks a million Charles - I'm gonna adjust the pilots - take her for a spin and then recheck the needles. Will keep you posted.
 

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Discussion Starter #17
Perfect -

I used a 135 jet which was way too big.

So I went down to 132 and I readjusted the pilots to 2.5 (They were out a lot more) And took it for a spin. Take off was way faster. I won't know for sure till I see how far in the mirrors the cars are at the light tomorrow :)
 

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Glad it all worked out. I'm running pod filters with stock exhaust, and I'm using 135 mains (kawasaki numbering). No other changes at all, other than turning the pilots 3 turns out from fully seated.

Charles.
 
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