Idle problems zxr400 L1

[thomas.dalton3]

Hi just got my first bike a zxr400 on the road from being sat for about two years. The problem being that it is only just running. The biggest problem i have, is the the bike doesnt seem to want to idle. When the bike is started from cold (which take forever to tick over and there is a strong smell of petrol) the revs will shoot up to about 2500 and take forever to drop back down. When they do eventually come back down, it will always drop to about 1000revs and sounds like its going to die on me. This doesn't just happen when starting up either. Every time i rev the bike the revs take forever to drop to the 1000 rev mark. Iv tried adjusting the tick over, but its either at the 1000 revs mark or it will shoot up to over 2ooo revs! The carb have been cleaned numerous times now, and iv done my best to balance them back in. But still hasnt affected anything. I have been told that if there is an air leak on the inlet rubbers it could lag the rev, but iv checked multiple times, and sparyed the inlets while running with easy start and am not getting any change in the revs, so iv ruled them out. Any advise/solutions to this would be much appreciated.
cheers, tom.

[RedexRobB]

what else have you done to the bike since collecting?

Really, you need the balancers to do a proper job. By eye isnt going to do it. So my advice would be to get a set of gauges roughly £30 on ebay. Also, check the throttle cables are in good shape, well oiled and allow the throttle to fully close. They could well be sticking. Sounds like the carb rubbers are good, but make sure the carb clamps are well tight too.

[thomas.dalton3]

Cheers for the reply,
Well since I've had the bike, the only things iv done to it are, change the plugs, oil, coolant and all the filters. And like i said, clean out the carbs. I should of mentioned before, that when i tried to balance the carbs, I did go and buy a set of balancing gauges, but the instructions which came with it are rubbish at best, so im not 100% sure that I set them up at all right. I did have it in the garage (which was a total waist of time in my eyes) but all they said they did was adjust the fueling and the tick over. To be fare its running better than before it went in but till sounds like a tractor on idle.
tom.

[thomas.dalton3]

oh and i dont think the throttle cables are sticking. oiled the cable, and on the side of the carb, the wheel which the cables pull goes all the way back to the stop or the the tickover adjuster

[RedexRobB]

If it goes back to the stop then that's good. Check out the workshop section on the main site. I have a guide I've written on how to balance the carbs.

[banner001]

where in the country are you?

i have a carbtune pro II balancer...probably the best you can get and i can get mine to well within 1mm Hg, im in coventry so if you are anywhere near us drop us a PM and if im not working you can come down and get you sorted

[thomas.dalton3]

Ok pretty much what happened is, I got a replacment set of carbs which iv been told are set up ready to run. There on the bike and now the bloody thing wont start at all.
All im getting is a huge bang (guessing a backfire),then the bike sounds like its going to start then nothing. Try again and the turns on the starter but wont do anything.
I've had the plugs out and they looked fine apart from there was petrol on the tips, im getting a spark off all plugs, so now im stumped once again!!

[banner001]

Ok pretty much what happened is, I got a replacment set of carbs which iv been told are set up ready to run. There on the bike and now the bloody thing wont start at all.
All im getting is a huge bang (guessing a backfire),then the bike sounds like its going to start then nothing. Try again and the turns on the starter but wont do anything.
I've had the plugs out and they looked fine apart from there was petrol on the tips, im getting a spark off all plugs, so now im stumped once again!!

carbs need to be setup for each bike. you need to see how your old ones are jetted, and compare that to the new ones.

one thing to test, is backfires can be caused by either too much fuel or too little, try firing the bike up with the choke on, if the bike is no different then you are probably running rich, but as you now have 2 sets of carbs take one (your old ones) apart and give them a damn good cleaning - i have done a guide on here. there are guides on the internet about how to setup keihin jetting, you will need to properly set the fuel heights, pilot settings and main jets for your bike.

as my sig says, i do a cleaning service for carbs, ive sold 5 sets of zxr 400 carbs on ebay so far, no problems so far, and ive helped out a few guys over the phone. PM me for the details if you dont wanna tackle them yourself.

[thomas.dalton3]

sorted now, just needed to clean them out, level out all the mixture screws to 2 and a quarter turns and balance. Running sweet
cheers for all the help guys.