Missing sparks and wont rev past 12k

[Simon2million]

Hi there, got a zxr 400 import H reg but first reg in 2001.

My bike appears to be running on 2/3 and sometimes all 4 cylinders, on tick over it appears to jump between 3 - 4 cylinders running, it wont rev past 11 - 12 k in any gear, put in new spark plugs, tested coils and pick up for correct resistance, all was correct. nice big spark from end of ht lead when jumping from lead to head for test purpose, tried new battery and still no luck. Speedo is in KPH, but has a ratio converter to adjust it to MPH so the speedo thinks the bike tops out at 100 kph when it is actually 100 mph. Compression test came good at 90, 90, 120 ,120 psi, all within tolerance. When i opened the carbs they all seemed clean, i ran brake cleaner through them and reassembled, they are all balanced, removed fuel filter and put tank straight to fuel pump, still no better.

I am struggling to think of anything else to check ! any ideas ?

I have a scorpion stainless race can, is it possible that it is not jetted correctly ? would that cause these problems ? what is the recommended jetting when using a race can ?

[masterofinsanity]

sounds a good chance that its not been setup for the exhaust, is it just a race can or complete system?

[Simon2million]

its runs 4 2 1 and just after it becomes one, it changes from steel to stainless steel, so with fairing on you can only see stainless, i have a photo i will upload. If it is jetting problems, what jets should i be aiming to use ? bigger or smaller than standard, and what is standard ? by how much bigger or smaller should i go ?

[masterofinsanity]

that looks like a standard system to me, don't think you need to rejet with just a race can, has it got a k&N filter??

[RedexRobB]

yeah, thats a standard system alright.

Has the bike always done it? Or since you did something to it? Check earth points are clean would be my advice, maybe a CDI issue if its jumping about on tickover randomly.

[Simon2million]

since i have bought it, i think, although i got it before i had past my test and started to strip and clean it up before i actually rode it, so i cant be sure if it was like this when i bought it because i didn't ride it. Hmm earths, id forgoten about that one, had issues with earthing on the jetskis we run, never even occured to me to check on that, was too busy trying the complicated things cheers mate, ill try it tomorrow and let u know.

So i shouldn't need to re - jet it with just a scorpion stainless end can then ? I will get some pics up of her rebuilt when i get round to it tomorrow cheers guys

[Simon2million]

checked the earth, that seems fine. and made no difference when i cleaned it up. How can i tell if it is a CDI issue, without buying another to try on it. I have measured the resistances as shown in the manual, however nearly all of them are not as they are written in the book. I noticed there seems to be several cdi units available, should they all read the same stated resistances as shown in the manual ?

[RedexRobB]

not entirely sure, i suspect they should be all the same. If you can borrow one then that will work out alot cheaper. Where abouts are you? Maybe another ZXR owner is local to you?

[Simon2million]

yeh my thoughts exactly, im in south yorkshire, near doncaster, but im also often around preston / manchester way, so anywhere in the north of england really ! any helpers ????

[bendog66]

Where about's are u mate? I work in chesterfield. That's probably as close as u'll get. i have 2 spare ECU's (both H and L). pm me if u want

[Simon2million]

pm cheers

[lindaloo]

near donny eh?? sorry i didnt see this sooner, i live down road in rawmarsh... do you get out and about on ya bike? dont see many floating round rotherham

[Simon2million]

yeh rode though wickersly and maltby about 5 times in the past 2 weeks.

[Simon2million]

Well a big thankyou to Ben Dog, on a very wet a misserable night he turned up on his own zxr , we unplugged my blue stickered L cdi unit, plugged in his blue stickered M cdi unit, and all was good, easily revs all the way round the clock now ! faulty cdi one must assume, will follow up with further tests when its dry to make sure everything is A OK.