Kawasaki Sportsbike Riders Club - Australia - Online Forum

im having problems with my streetfightered zx9r (2000). Under load it struggles (as if about to run out of fuel)...especially noticable when going anywhere above around 80kmph. Just wondering if anyone could give me advice on what could be causing the problem. Important notes:

- was stored for year but dont know if was like it beforehand
- carbs are clean and balanced
- got new spark plugs
- fuel pump seems to be working fine
- and fuel hoses are clean and not kinked

Te only thing i can think to be causing this could be the removal of the ram air ducts, or problem with the insulation of the spark plug caps.

If you have any experience or know of this problem id love to know of how to fix it.

Fuel lines may be fine but have you checked you haven't trapped the breather from the tank ?

Grab ya spare key and just pop the filler open when it starts to feel sluggish and see what happens.........a lot easier than pulling the tank off to check

May be something to do with removing the ram air tubes.
I had a similar problem where the vacuum tubes for the carbs (part of the ram air pipes) weren't connected properly.
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fuel filter perhaps?

i've heard that there are complications in making a zx9 a streetfighter because of the ram air. the system that works so well with the ducts seems to work so poorly with out them.

i cant remember what the cause was, but it possibly has something to do with the two trumpets in the ducts and whatever they connect to. thats my guess? possibly some kind of pressure compensating thing-a-me-bob?

I am sure there was a thread about this type of thing, but the problem was with a street-fightered ZX7R ?? It may have been lost in the 'Great Crash of 2005', but I am sure that MBP was the source of some great info regarding the way to fix this ?

I am also 100% sure that you can find the answer on http://www.zx-12r.org

and look under the ZX9 section, Techincal threads.....

Good luck mate

do you still have the trumpets sticking out of the airbox thru the frame€€? its possible they are getting a slight ram air affect and its pressurising the airbox, but the balance line that goes back to the carbys isnt getting pressurised therefore the fuel is getting pushed out of the carbys when your at speed.. making it run lean


maybe try pull the trumpets out all together, and do something with the balance line too

thanks everyone, that info should prove useful...ill have a go at what you guys said and let know ...

do ya think itd be electrical at all? eg spark plugs caps not insulating properly so sparking badly under load?

ive also checked the filter and its clean

It will be from removing the clean air intakes in the ram tubes..
The ram tubes have a smaller rubber tube in them that goes to the carbs if these are removed the bike will run crap..
I know as I forgot to hook em up a few times and the result is as you have described...
The pic below shows the bits I'm talking about

and don't listen to Gosling, all your problems can be resolved here...

Neka is our relationship councillor..

try stick all the ram air gear back on, you'll know pretty quick if its better

i was just looking at that air digram and just wondering if anyone could tell me what the part 3213 is... its a connecting pipe from the rubber carb hose to the intakes at front...curious s to whether it helps pressurise or not.

bike was in an accident so most of front fairing is damaged badly of missing previous owner was didnt bother to keep much of the damaged parts

also looking the zx12 site they reckon that low battery charge could be the problem...my battery doesnt seem to be the correct one (ie it needs to be slanted to fit with seat on)... could anyone tell me the correct bttery that i need? (worth getting the right one anyway, even if it dont fix problem)

you mean 32153? they are the little tubes that sit in the air intakes and take a sample of the air comming in and send it to the carbys.. when the bike is moving real fast the air in the ducts begins to build up pressure, and it needs a balance line to go into the carbys so that as airbox pressure increases, so does fuel pressure so that the fuel wont get pushed out of the carbys


im sure if you pulled off the intake trumpets and the balance line then the bike should perform exactly as it would on a dyno (130rwhp+) cept there would be no extra boost as speed increases


low battery wouldnt be a problem, the batterys only real purpose is to start the engine, once the engine is running your electrical power comes from the bikes generator+reg/rec

well time for some good news...those of you who suggested pulling off the ram air trumpets were correct. (I already had the carbie balance hose off)...bike runs perfectly now, and if any of you come to townsville i shout ya a beer (or ten)

just curious though, will any permenant damage occur if i run it this way?

YES... your licence will be a little safer without that extra boost that you can really feel when your redlining 4th