Tickover and reving out

[garyzxr400]

Hi there i have had a scan of other posts and cant seam to find an answer to my problem so hear go's.
I have a ZXR400L1 and it seams to struggle to tickover. Eithere you turn the idle up and it screams its nuts off or you turn it down a bit and it cuts out when you come to a stop or slow down. (managed to stall twice coming down hill on tuesday by just coming off the throtle). We have tried striping the carbs and cleaning the jets a few times, balenced the carbs, replaced the throttle cables and changed the plugs. Changing the plugs helped for a while and then it went back to normal, need to strip plugs out to have a lok but was looking for any further advice as well.
Also problem number 2 is that when i open it up i get to around 1200rpm and the bike seams to and spluter it kind of jerks forwards and dies and goes again till i change gear. not sure if these two problems are related or not but any help would be greatly apreciated.

[unclesparks]

I had that problem on my NC30. New cdi did the trick. Also leads on the coils can make a difference.

[RedexRobB]

What were the plugs like when you last took them out? Sounds like fuelling to me.

[zimm]

check your fuel filter, i had one do that and the filter was utterly blocked .. sustained high revs and it would cut out then pick up then cut out then pick up as it repeatedly ran out of fuel. is your fuel pump sounding normal ? should tick a bit at startup then go quiet with an occasional couple of ticks as it refills the float bowls, if it seems to be running constantly/getting hot there's a problem.

[jake]

or could just be running a bit rich, has anyone adjusted the pilot screws on the back of the carbs?
Make sure they are all set to standard, 1.5 turns out i think ( anti clockwise ), and adjust from there.
Check the filter like zimm says, i take the filter out all together meself, not sure what its there for. The zxrs have a filter in the tank.

[zimm]

i take the filter out all together meself, not sure what its there for. The zxrs have a filter in the tank.

well, they catch enough crap to justify their presence as far as im concerned.. on a road bike anyway, track bike it doesnt really matter as (hopefully) you have a clean tank and decent fuel.

[jake]

aye, i spose your right, i never thought of that... the one i took off my bike was filthy too, got me worried now!

[garyzxr400]

thanks for all the ideas will give them a go. i think we had the air mixture screws out when e cleaned the carbs so may have put thim in to far or not far enough, will try a new fuel filter as well, cant remeber what the plugs looked like when we took them out last time. and i have a spare cdi unit kicking about as well so may chuck that in. thanks guys