[derbyblueboy]

Help please guys, Got me an f3 zx6r cheap. It runs fine upto about 6rpm and then feels as rough as fcuk with no power until you you get to around 8rpm (as if it's not firing on all cylinders) and after that it goes great. It had a Devil race can on with a K&N filter when i got it, I've taken both these off and replaced with the stock items but no difference, ant ideas, cheers Steve

 

[ginger.ninja]

try getting your carbs balanced, and a good service, oil etc. This normally helps.

 

[BikePilot]

CV carbs are known for causing issues like that when they are partially plugged up or the CV slides aren't moving as they should. I'd start with a good carb clean and inspect the rubber diaphrams and see where that gets you.


good luck

 

[getshawty]

sorry derbyblueboy to jack the thread but im from notts just down the A52 from you,
small world

 

[lee6r]

Sounds like stale fuel deposits in the carbs to me mate.
Whip off your tank, whip off airbox and then spray some carb cleaner directly into the bellmouths with the engine running ( should be enough fuel left in carbs for a good few minutes worth of spraying ).
THAT SHOULD DO THE JOB.

 

[amb67]

Hi,

I have an F3 model ZX6R and had almost the same issue last year, I started by giving the bike a good service, oil, plugs, fuel filter, oil filter, air filter (K+N). This made an improvement but still didn't get rid of the spot between 6k - 8k RPM, I decided that as it was popping badly through the exhaust I would check the valve clearances.

When I stripped the top end down I found that on virtually all valves no clearances existed. I set up all the clearances in the end, it is certainly not a job for the inexperienced home mechanics and that made the bike roar once more. All I had now was a slight flatness throughout the rev range.

I rectified this the other week by balancing my cards, this was very easy and I would recommend all ZX6R owners do this at least once a year, the difference was amazing.

In light of the above I would recommend the following in this order:

Full service
Check and adjust valve clearances (If not been done in past 2 years 8K miles)
Carb balance

= What seems like a new bike

Have fun!

If you have any questions about the stuff I've done to my bike just ask!

 

[derbyblueboy]

Cheers for your help, I will give it a go, although I think I'll get me mate to do it! What are the front brakes like on your's, mine seem really spongy, theres good pads n discs, goodridge braided hoses and I've tried bleeding them, even replacing all the fluid but I can still pull the lever right to the grip! They do stop me ok but just don't give me the confidence I would expect. Again cheers for your help, Steve

 

[amb67]

I had crap front brakes on mine when I bought it, I also replaced the hoses for Goodridge braided ones and it cured the problem.

If you have already done this and bled them correctly then it has to be a master cylinder problem, you shouldn't be able to pull the lever back to the bar at anytime.

I would suggest bleeding the brakes again before going down the route of the master cylinder seals. It sounds like it may just be some trapped air, mine was an absolute pain to bleed after fitting my braided hoses. I guess I got through 2 litres of Dot4 before I had a half descent feel to the brakes.

A couple of questions I have are :

Does the lever get harder if you operate it several times?

Does the lever sink back to the bars after doing the above and holding on the pressure?

This will hopefully helps us narrow your problem down.

 

[derbyblueboy]

Hi again, the lever does get slightly harder when pumped several times and stays there when held, cheers

 

[lee6r]

After pumping brakes to get a hard feel, release the brake, push the bike for about 2 revolutions of the wheels, is it still firm or gone mushy again?
If now soft and mushy then you probably have warped discs, ouch!
I warped 2 sets on my 99 model, NOT CHEAP!

 

[amb67]

Hi Derbyblueboy,

I,m afraid Lee6R may be on the button with this one. The F3 ZX6R does tend to eat discs, I am sure all other F3 owners would agree!

A set of front discs for these models can cost as little as £114 per side or as much as £200 per side. My advice is buy the best you can afford!

Try this site for good discs: http://www.moto-racing.co.uk/cat--Kawasaki-ZX-6-Ninja-Brake-Discs--All+ZX6+Brake+Discs.html

 

[Loesch]

With the flat spot, I would also try jumping it and giving it some revs. A buddy of mine got an older Honda F3 and that happened due to not enough spark. If you would jump it, it wouldn't die out at all. Maybe just a new battery?