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carb adjustment

Posted: Tue Mar 20, 2012 10:18 am
Author: bunnysZ
bought some carbs of ebay for the Z1A, cleaned them up inside , no leaks. put them on the bike , but the bike is racing away a bit fast when turned over even without any choke and the idle adjustment knob isn't touching the anvil lever,
so what needs adjusting to bring fix this problem.

Posted: Tue Mar 20, 2012 11:35 am
Author: kev edwards
The slides are probably way to high and all need lowering, take the carbs off and sync the slides on the bench like it says in the manual making sure you have lowered the slides at least half way through their adjustment prior to set up, hope you understand this, had this problem myself once.

Posted: Tue Mar 20, 2012 11:42 am
Author: CAT3
I'm not sure if those carbs don't have individual "closed-throttle stoppers" as well as the one overall throttle-stop srew, which would need checking first. (My Z900-A4 is different anyway).

I'd also check that all the correct jets are fitted for your model Z1. These should be main-jet = 112.5, air-jet = 1.0, needle-jet = P-8, main-jet = 5J9-3 (the 9 indicates a lot number & may vary), pilot-jet = 20, throttle-valve cut-away = 2.5.

Also check the air screw of each carb should be approx. 1.5 turns out from the fully closed position.

Then check the balance as that too can cause high idling.

Posted: Tue Mar 20, 2012 4:11 pm
Author: bunnysZ
bike is standard 4 into 4 exhaust nd all correct jets as above

Posted: Wed Mar 21, 2012 5:06 pm
Author: bunnysZ
slides now adjusted , (difficult finding anything 0.7mm,) also moved needles to centre notch and adjusted throttle stop. all this has improved it , but still idles at 1800 revs when standing , top end speed is great , but when tou come off the throttle and just slightly on again it sort of stutters a bit ,
any suggestions on this.