ZX9R Rough running

[WanaGo]

Hey all,

Can people please give me some help/advice on what I should/could do about my 97 ZX9R running rough at low speeds, and at idle.
After I have ridden it for a bit, the roughness gets worse - still fully controllable, but its not running very nicely at all. Jerky sort of feeling, with a 'rotary engine' sort of sound. Sort of like a two stroke that is 4 stroking - if that makes sence.

I was just wondering if anyone knows what the best way to fix this would be. The carbs were apparently checked by Rodney Motorcycles in December 2004, just before I brought it. They did a $659.07 service on it, with the following details:

Service
Fit Alarm
Check Carborators
Replce Clutch lockout switch

Oil Filter
Spark Plug x4
Antifreeze
3.5L engine oil
92180-1026 Shim
92180-1024 Shim
Clutch switch
Freight
Total $659.07 - with Labour being $425.00

So by the sounds of this, the carbs have already been checked, so I dont get what it could be. One bike shop said they could need balancing, but then couldnt understand why it would after seeing this service docket. Another said the jets may be worn or something like that.

If anyone could recommend me something, it would be appriciated. I dont have alot of money to spend, so I want to get this right the first time.

Bike is really smooth and very peppy when it gets going, its just at low speeds its a bit funny - but doesnt seem to matter if you are in 1st, 2nd or 3rd going around town, like the revs dont alter it. So I dont get that.

Recommendations?

Cheers
WanaGo

[Monsterbishi]

Just because it lists something as being done, don't assume it's not the problem... Quite often, in the hands of a non-so-flash mechanic, they can just turn into a timebomb, good for a short while - then fail soon after.

[WanaGo]

If it was running slightly rich, could this cause the problem ?

Cheers
WanaGo

[WINJA]

If it was running slightly rich, could this cause the problem ?

Cheers
WanaGo

LOOK IN THE RAM AIR YOU SHOULD SEE TRUMPETS , TRACE THIS PIPE IT SHOULD GO TO THE CARBS , MAKE SURE IT IS NOT CRIMPED BLOCKED OR DISCONNECTED. CHECK THE AIR FILTER MAKE SURE ITS NOT OVER OILED OR TOO DIRTY. I GOT MORE HELP IF YA NEED IT , I LOVE KWAKAS. HAVE YOU GOT A STOCK PIPE? WHEN WERE YOUR PLUGS LAST DONE? HOW MANY KS?

[WanaGo]

LOOK IN THE RAM AIR YOU SHOULD SEE TRUMPETS , TRACE THIS PIPE IT SHOULD GO TO THE CARBS , MAKE SURE IT IS NOT CRIMPED BLOCKED OR DISCONNECTED. CHECK THE AIR FILTER MAKE SURE ITS NOT OVER OILED OR TOO DIRTY. I GOT MORE HELP IF YA NEED IT , I LOVE KWAKAS. HAVE YOU GOT A STOCK PIPE? WHEN WERE YOUR PLUGS LAST DONE? HOW MANY KS?

Hey,

Thanks - Ill check them tomorrow.
Any more suggestions?

Not a stock pipe no. But it has had it on since 2003. Plugs last done in the service mentioned above - 4 new ones ($86.40)

** www.taktik.co.nz/bike/ has the pics of my bike **

Cheers
WanaGo

[WINJA]

Hey,

Thanks - Ill check them tomorrow.
Any more suggestions?

Not a stock pipe no. But it has had it on since 2003. Plugs last done in the service mentioned above - 4 new ones ($86.40)

** www.taktik.co.nz/bike/ has the pics of my bike **

Cheers
WanaGo

I HOPE ITS NOT THE CARB DIAPHRAMS BUT WHAT EVER YOU DO DONT PULL THE TOPS OFF . IT MAYBE AS SIMPLE AS A LOSE MAIN JET.

[WanaGo]

I HOPE ITS NOT THE CARB DIAPHRAMS BUT WHAT EVER YOU DO DONT PULL THE TOPS OFF . IT MAYBE AS SIMPLE AS A LOSE MAIN JET.

Righto. What sort of price is something like the carb diaphrams? I take its not a nice figure.
Would something like the RAM air cause something like this? And to be the cause if it being worse when it gets hot... ?

Ta
WanaGo

[**R1**]

Yeah i would say check the airbox for sure....every time i got my kwaka serviced they would crimp the intake trumpets,,,,in the end i gave up and started servicing my own bikes, i also had probs with the leads....for a while i would change plugs to fix a low rev miss, the a few weeks later it would reapear, in the end i replaced the leads, and caps and it sorted the miss......

[WanaGo]

Righto - ill check the airbox.
Hope this is just a simple problem.

Thanks
WanaGo

[WINJA]

Righto. What sort of price is something like the carb diaphrams? I take its not a nice figure.
Would something like the RAM air cause something like this? And to be the cause if it being worse when it gets hot... ?

Ta
WanaGo

DUNNO WHAT THE DIAPHRAMS COST BUT WHEN I PULLED MINE OUT THEY WOULDNT GO BACK IN AS THEY HAD STRETCHED THERE IS ANOTHER WAY TO TEST THEM IN PLACE. BUT IF ANYONE DOES HAVE THIS PROBLEM I HAVE A FIX.
IF IT GETS WORSE WHEN HOT IT MAY BE RUNNING RICH. AND YOU MIGHT ASK HOW CAN IT BE RICH NOW WITHOUT CHANGING THE JETS. WELL I HAD A ZX9 WITH HIGH KS AND THE NEEDLES STARTED TO WEAR OUT WHERE THE MAIN JETS GO

[PSYCHO]

Has the symptoms just shown up? if so have you done anything to it? or has it been like this since you've had the bike?

You say it runs rough at low speed and idle? If there is a problem with the trumpets/hoses this will effect running at speed but NOT at idle.
When it's running rough/missing shut it off and check the exhaust headers and see if one (or more) of the pipes are significantly cooler than the others. The cold pipe will tell you what cylinder is the problem.
Like Aaron says the plug lead could be the culprit here, I had a dodgy lead on my 96 7r which displayed similar symptoms to what you describe.
I'd also make sure the idle mixture screws are set correctly.

[WanaGo]

Has the symptoms just shown up? if so have you done anything to it? or has it been like this since you've had the bike?

You say it runs rough at low speed and idle? If there is a problem with the trumpets/hoses this will effect running at speed but NOT at idle.
When it's running rough/missing shut it off and check the exhaust headers and see if one (or more) of the pipes are significantly cooler than the others. The cold pipe will tell you what cylinder is the problem.
Like Aaron says the plug lead could be the culprit here, I had a dodgy lead on my 96 7r which displayed similar symptoms to what you describe.
I'd also make sure the idle mixture screws are set correctly.

Hey,
Well I have only owned the bike since the end of Jan, but have been waiting for my licence to arrive as I did the CBTA Full course to cut down the time. Finally arrived on Monday, so I have only been riding it this week.
I have a multimeter that came with a temp probe, capable to read up to 1000 Degrees. Ill stick that on each header pipe tomorrow and read the temps.

Plugs are apparently just new, but I could check them I suppose. In terms of leads, Ill find out if the pipes are different temp first.

Cheers
WanaGo

[inlinefour]

on a new fireblade? (PT).

[Slingshot]

James...It better be running on Sunday...cause we're coming up and it'd be rude not to go for a ride!


To check that all cylinders are firing, run the bike for a couple of minutes and get a damp cloth and dab that against the header pipes...it'll be really obvious if one of them is cooler than the others.

Ram Air...there's probably two seperate systems (seperate enough anyway), one is the big ram air ducts that pressurise the air box at speed, the other will be an intake for idle and low speeds (normally below 15kms). It could be something to do with that.

Pull the plugs out and you should be able to tell by the colour of them if it's been running rich or lean.

If you want to have a look at the carbs I can give you a hand this weekend, I've had the carbs on my old bike apart heaps of times and know what to look for now.

[mattt]

I was just wondering if anyone knows what the best way to fix this would be. The carbs were apparently checked by Rodney Motorcycles in December 2004,

Bloody hell - not you too?
I brought a bike of Rodney Motorcycles last year, and had major major mechanicals costing upwards of $2000.
They're lying scumbags that don't know shit about bikes.

I took them to court under Consumer Guarantees Act & Fair Trading Act, and won.
I also added 2 tyres + chain & sprocket set to their bill, which they had to pay FUCKERS!