jrobert13

Hoping you can Help Harry?

To preface, here is my set-up, questions to follow. I have a 1990 Kawasaki X2 with a 95 Kaw ZXI 750 motor. Westcoast pipe, WC waterbox, aftermarket flame arrestors. Stock compression (145, 143). Dual carbs, CDK II. All electrical came from the donor ZXI. Jetting is stock for the ZXI 750 - (verified in another thread). Stock 1990 X2 pump and prop from what I can tell.

Was hoping you would know the appropriate pop-off for the carb? Read in another thread that it should be up around 40 psi? If so, what spring do you reccomend to start with? I verified jets to stock, but can not find any info on the pop-off. Even checked the dealer service manual for the ZXI 750 (no mention of pop-off). When doing initial pop-off testing, bubbles formed around the needle seat - further inspection revealed bad O-ring's. Have replaced O-rings and pop-off was on average 38 - both carbs. I actually rode it like this for 20 min the other day with the bad O-rings. NO power, but would rev fine on trailer. Hoping this will solve all my problems? Water line routing was also mis-routed - previous owner.

I started in garage tonight for a few seconds. Bottom seemed to fall on its face. Motor obviously cold. Lean if falls on its face, and rich if it stumbles right? Low needle is currently 3/4 out and High needle is 1.5 out. Going to try to lake test tomorrow. I have minimal experience with Keihin carbs and can not find any good info in any threads related to tuning these carbs.

Thanks for your time,
Joe

jrobert13

Update - I did an extensive trailer test today. Here are the results... Was dialing in the low end. Let engine warm up to operating temp then held at 1/8th throttle for about a minute (had occasional blurps and hesitations). Hit the kill and checked the plugs. Mag plug was a chocolate brown, PTO plug was chocolate and had some oil residue on the outer ring. Made extremely small adjustments and retested (my experience with mikuni roundslides on snowmobiles had small adjustments played huge). Continued to turn in Mag and PTO 1/16th turn at a time (identical). The PTO carb adjustment is extremely difficult to adjust. Going to fab up something at work tomorrow. I have read that each carb has to be identical in other threads and am unsure of how radical I can get with the low/high adjustment without burning it down. Finally had the Mag carb about perfect, but was still having oil residue on outer ring of PTO plug. Then adjusted high. Mag carb is about cherry, but PTO is still rich with equaul adjustments. Can I have them not be identical?? When felt I had it good would simulate riding on the trailer, was still sluggish and wouldn't rev all the way up (but wayyyyy better than before). If I held at 3/4 for a 10 seconds and then full WOT the thing would come alive and scream on trailer but would not rev all the way up if you went from 1/8th throttle?? Thoughts? Took out for test run (long no wake zone). Got out in the open, rode for 30 seconds and fouled PTO plug. Got dark and had to head home. All help would be appreciated.

Thanks,
Joe

motoman96

check this link out. I also think your popoff isstill too high.
http://www.keihin-us.com/am/_media/pdf/cdk_jetting.pdf

jrobert13

Thanks for the link motoman96. Bought some plugs at lunch today. Hoping for tuning trial # 2 tonight.