ZXR 400 won't rev pass 6000 rpm

[kabatza]

High guys,

I just picked up my ZXR400 from the insurance company (stollen and recovered). It has some fairing damage, but nothing I can not fix.

The ignition switch has been replaced with a different one but seems to work fine. the petrol tank had some water in it but not rusty or anything, and the rear tyre is nearly bald, although it has only done 400km since stollen. also the chain and the disks were rusty as itn hasn't run for 6 months.

I cleaned and greased the chain, changed the oil,charged the battery, filed it up with fuel and pressed the ignition................. 30 seconds later it started just fine with the chock on.

After it warmed up, I switched to idle and it seemed just fine. I tried to rev it and it died just over 5000rpm. It will rev stady until 5k-6k but any higher it cuts out!

Anybody has any ideas????? I 've never came accross this problem with any other bike.

I just want to add that it seems like an electrical problem because everithing is fine until it reaches 6000rpm.
do you think it is the ignition switch????? i've heared that the zxr400 havs an anti-theft protection inside the switch.

[masterofinsanity]

i've never heard of any anti theft protection in a zxr400 before? is it always bang on 6000 revs?

[NickT22]

Might be a stupid question as the bike was stolen, but does it have an immobilizer on it?
I had a Datatool duo on my last bike which went faulty and at bang on 9000 RPM the vibration through the frame triggered the relays and shut the bike down. Spoke to Datatool at the NEC show last year and they say that it's common if the immobilizer has no padding beteween frame and control unit isolating vibrations.
Another possible cause could be dirt in the carbs or fuel filter preventing a decent flow of fuel through, do the revs just stop dead or before cutting out does the RPM get a bit rough?

Hope this helps,
Nick.

[sloweracing]

Try changing the E.C.U it might be dud

Coils do break down as well but i would start with borrowing a ecu from some one that you know that has one working

Good Luck

I'm in Sevenoaks nr brands if that helps

[chrisu]

mine did this and i thought it was electrical. but a friend came round one day and fixed it. what he did was hold the throttle until it was about to cut out. and kept trying to give it all he could. the revs started to rise slowly and eventually went all the way. then put some carb cleaner in the tank and all is fine now.

[Guest]

Yahoo!!!!!!! I fixed it!! I did all what you guys said but I think its what chrisu said. dirty carbs! I threw the datatool away as well just in case.

I was thinking.....how come it idles so well but does not rev at all. I also noticed that it would rev upto 6k but then while trying to rev it without stalling it the revs were decrising until I could not rev it at all. Restarting it and all the same again.

then I was thinking how the carbs work and it just came to me.... must be the main jets.

To tell you the trouth I cannot believe how much crap it had in the carbs. The floats were half full with some brown liquid (no way that was fuel!) It was more like jelly than liquid and very dark brown.

I took the carbs apart to the last screw and cleaned them with carb cleaner first and then hot water. I made sure they looked like new and then put them back and started the bike. I did not notice anty change but kept insisting ....... 5000rpm......6000rpm......7000rpm ...... realised something is happening......kept reving it .......and brooooooooooom 12000rpm, now it sounds great.

Now the last thing I have to work out, is why my front indicators are dead and then i can ride it again.

Thank you all guys for your help!!!

[Bikerz]

gd old brown stuff in carbs, i got that in my sv when she was stood for about 3 years, the carbs where horrible, i wouldnt recomend cleaning them with water tho

[chrisu]

yay!! i helped someone im so glad my friend did this to my bike, otherwise id have a big mechanics bill and wouldnt have been able to help you.

[Miller]

Yer petrol can turn to jelly like stuff if you leave it stagnant in your carbs for too long so should always run it empty if you gonna leave it for months on end