ZZR1100 C Sticking at 7000 RPM

[Echoeone]

Hi - ZZR1100 C runs nice on tick over, have balanced and cleaned carbs, changed oil and oil filter and given her new plugs. I have also put different coils on. Problem is though that when it gets to about 7000 rpm under load, it just wont rev any higher and just sticks at those revs till u change gear - its the same in all gears as well. Acceleration is also not what it should be. It is as if it is running on 3 pots but is actually on 4. There is no excessive smoke etc. It has the flat carb tops so is unrestricted.

Any ideas or thoughts would be v welcome on what the prob could be and ideas to poss fix.

thx

[Pete]

Could it be clutch related? Maybe the plates are worn or the cable is too tight, thus not allowing the plates to close together firmly?

[Guest akey]

simple one, but has it got fresh fuel in it??

[Echoeone]

Hi thanks for your help guys - yep new fuel in her. The clutch isn't slipping and is hydrolic. At low revs it sets off quick enough but fades at about 5000 and crawls up to 7000?

[Pete]

Clogged air filter? I did think maybe a kink in the fuel line but I 'spose it wouldn't be having a consistant problem in every gear then...?

[kja.busa]

Tank breather blocked? Its fuel related as Akey hinted at, kinked fuel pipes? Fuel filter in the tap blocked or partially obscured?

[Echoeone]

I'll have a good look at the fuel pipes/filters/pump etc and post back

thx

[rosszx9r]

when it gets to about 7000 rpm under load, it just wont rev any higher and just sticks at those revs till u change gear

it sounds like a blocked air filter to me.

does it rev beyond 7k when stationary?

[rosszx9r]

when it gets to about 7000 rpm under load, it just wont rev any higher and just sticks at those revs till u change gear

it sounds like a blocked air filter to me.

does it rev beyond 7k when stationary?

[Echoeone]

Hi thx for all the replies. Have taken the fuel lines and fuel pump out and checked - plus the various tank breathers/filters etc. The prob looks to be the pump as not much comes out the other side when tested. It also looks as if it has been pumping rust in the past from a dodgy tank. Will fit a different pump and then test it on the road again. Have the air filter off and that makes no difference so will continue with fuel supply as the main suspect

thx

[kja.busa]

Theres probably at least one filter with in the pump itself, it maybe just a case on dismantling it and cleaning the filters, I did this to a Hayabusa pump last year and there were 3 filters within the pump, ranging from a paper element to a couple of guaze filters, worth a look, it may save you the price of another pump.

[Guest]

I had very similar symptoms with my Kwak ZX10R (2005), tore hair out until almost bald trying to trace the problem. Took it to several 'specialists' then eventually bit the bullet on Kawasaki diagnostics. Turned out to be two of the secondary throttle bodies stuck completely. Kawasaki wanted £2000 for new parts, needless to say I got the same on Ebay for £100. Bike now happy and will rev and even go over the national speed limit now! Hope it is the fuel pump, will be much easier and quicker to fix!

Good luck!

L.

[Echoeone]

Pulling my hair out with this one. Still acts as if its restricted at 7k rpm. It has flat carb tops though - so if it is restricted thats not how they have on this one. The bike is a foreign import. Has anyone come across them being restricted in any other way eg via CDI unit or other means with it being a non uk bike? All other things we have talked about re fuel etc have checked and these are all ok following a different pump and new lines etc so a real mystery.

thx

[rosszx9r]

Pulling my hair out with this one. Still acts as if its restricted at 7k rpm. It has flat carb tops though - so if it is restricted thats not how they have on this one.

a number of kwaks are restricted in the carbs. the carb lids have ridges (~5mm high) that stop the carb slider lifting fully. this only affected early zzr1100 as it was during a time of voluntry restrictions to 125bhp. that restriction was forgotton about a long time ago now

that still shouldn't limit revs under load though.

couple of areas that could be at fault are the coils or HT system in general. a weak spark will rob engine power and only show up under load. could be a faulty plug, ht cable or more likely a coil.

the CDI unit could also be faulty but that is much less likely.

i've checked my haynes for my zx9r (same engine design, same ignition system) and they suggest the above ignition components too but also mention a few other areas where low power under load could occur. these are:

air leak on carb intakes

incorectly set or type of spark plug

sticking throttle body

incorrect engine oil (too thick causing engine drag)

going back to your origonal post, you suggested it was running on 3 cylinders. quite possibly!

i think you have ruled out the fuel delivery system, suggest you focus on the ignition system now. take the plugs out and see if one is a different colour to the rest (do this after a run when you experiance the problem)

you should also inspect the ignition pickup incase it's damaged or contaminated with oil (sits on the end on the crankshaft in a sealed chamber). check the condition of all HT components. looking more closely at the one where the plug is discoloured.

the only other suggestion i have at this point is the carb diaphrams. if one is damaged or not sealing correctly then it can stop the throttle slider from opening. since you'll have to remove tank, fairing airbox to get at the plugs, the carbs diaphrams can be easily tested. using your finger (while the egine is off ) slide the carb slider up then let it drop back down. you should get some resistance when pushing it up and it should also make a swishing sound as you move it (air going in and out of the carb top) and obviously, the slider shouldn't stick anywhere.

hope that helps

[rosszx9r]

THIS might help you identify all the ignition components.

[Echoeone]

Thanks for the help and will look at the areas. One last observation is that it is not possible to rev it over 7k rpm when stationary. Not that I make a habbit of it - but tried it folowing a previous suggestion to see if it would. When i did it the engine fell away at 7k rather like it would if u put the choke on when it was warmed up with the same kind of noise change. When the engine is idling or at lower revs it sounds perfect.

[rosszx9r]

One last observation is that it is not possible to rev it over 7k rpm when stationary.

seems like you will really have to do a plug chop to find out which cyliders are causing the issue.

if you can bear the noise, warm the engine fully, rev it to 7k while stationary and hold it there while it misfires for 20 - 30 seconds. then hit the kill switch and take the plugs out. check colour. this is normaly done with the engine under load but since you have the issue with no load, it should work ok.

you should hopefully find two of the cyliders have black deposits on the plugs which should tie in with the coil associated with them so you can narrow down the list of things to replace. if they are all the same then you should look for a new cdi box or ignition pickup.

[Pete]

Whilst reading up on the ZX9R (considering next bike, as always!) I was reading about common problems and found this:

PLUG CAPS

Number one cylinder's plug cap can come loose, meaning the bike will run on three cylinders until around 5000 revs. Pop it back in place and all's fine.

So even though you say it's running on 4 but seems like three have you checked that? The plug might be working but the cap might not be pushed in far enough...I hope it is that simple!!!

Here's the website I found it on btw:

http://www.visordown.com/road-tests-use ... /4316.html

[rosszx9r]

just a thought but have you checked the battery charge?

if it's low or the alternator isn't working you could be getting a really weak spark. battery volts should be 13 - 14v with the engine running