Page 1 of 1

Need help idle problem

Posted: Sun Sep 07, 2014 6:36 pm
by craig
hi guy's

right i've had my zxr 400 l model for a little over a year as my first restoration

brought the bike as a spare or repair due to the wiring loom burnt out however it was in a very bad state so i decided to completely strip it back and start again any way its near completed but have a problem with it idling correctly if i turn the idle screw so it idles at 1700rpm as soon as i rev the bike the idle wont drop below 2500 - 3000rpm

any ideas would be great

craig

Re: Need help idle problem

Posted: Sun Sep 07, 2014 7:18 pm
by zimm
idle should be about 1200rpm,

if its hanging above wherever you've set it before dropping back, or just refusing to drop back its either,



too lean, richen up the pilot circuit
too lean because its got an air leak

carbs being out of balance will exacerbate either of the above
valve clearances want to all be close to each other rather than just "within range", clearance affects opening time and the amount of vacuum available at the carb to draw fuel in/lift the slide

or it could just be a sticky/snagging cable/throttle mechanism.. or even.. a damaged butterfly valve in one or more carbs,

Re: Need help idle problem

Posted: Sun Sep 07, 2014 8:20 pm
by craig
thank you for the reply well i know there isn't an air as check that first nor sticky/snagging cable/throttle mechanism due them all being new how ever the valve clearances is due so as soon as i get my body panels back from the paint shop i will take it to my local bike shop for them to check the valves and replace the cam chain and stick it on the dyno and balance the carbs and check mixture ;)