ZX9R Rough running [Archive] - Kiwi Biker forums

WanaGo

10th March 2005, 17:27

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

10th March 2005, 17:38

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

10th March 2005, 17:44

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

Cheers
WanaGo

WINJA

10th March 2005, 18:57

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

10th March 2005, 19:18

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

10th March 2005, 19:31

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

10th March 2005, 19:36

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**

10th March 2005, 19:40

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

10th March 2005, 19:47

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

Thanks
WanaGo

WINJA

10th March 2005, 19:57

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

10th March 2005, 20:46

WanaGo

10th March 2005, 21:59

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

11th March 2005, 04:47

on a new fireblade? (PT).

Slingshot

11th March 2005, 08:16

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

11th March 2005, 09:13

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 :2thumbsup FUCKERS!

WanaGo

11th March 2005, 10:15

Thanks John,
Going to the beach on Sat and staying the night, and will be back on Sunday. When are you coming up?
The bike is fully working, its just a bit rough thats all - like nothing major, its just a concern to me that its not right.

Mattt - bugger. That sucks. What sort of problems did it have? What bike?

Cheers
WanaGo

trev

11th March 2005, 10:30

WanaGo

11th March 2005, 10:48

my 9R doesn't like running below 3000 rpm & is real unhappy below 2500 rpm. They are known for this.
check out www.zx9-r.net/nav.htm
If it is not running really rough it may not need tinkering with.

My bike cuts out completely for periods every now & then. I've by-passed the sidestand switch ( evidently they play up ) & so far it has run O.K.
Oh ok,
Surely its not ment to run like it is though, negotiating slow corners is a bit of a bitch when its jerky - do able, but not that plesent.
Yeah mine cuts out every now and then too, esp when starting it up after its rested for a short period of time, ie not cooled down completely. Like you start it, about to take off, and it stops, try again, same thing. End up I just put on choke again for 10 seconds until the revs suddenly shoot up, and turn it off and then go. Seems to work, but really odd.
What can the side stand do if its faulty?

yours is a 2001, and it runs like this too?

Cheers
WanaGo

vifferman

11th March 2005, 10:59

This isn't a helpful comment - I'm just gloating. :cool: Sorry....

My VFR was running rough at low revs (lean surge/stumble). Last night while I was checking the tyre pressures, I disconnected/reconnected the battery negative and voila! (Bingo!) - it's all fixed. It reset the ECU, forcing it to actually pay attention to the sensor readings instead of going, "Yeah...{yawn} - I know this one: air, fuel, stuff like that...{snore}..."
So, it was, "WTF?!? Someone's been fiddling! Engine room? Send some more coal to the boilers!"
(This is in response to me fitting the new "NaughtyButNiceZorstRestrictor" to the Satantune. :devil2: I thought it wouldn't make much difference to back pressure/mixture, but obviously it did. :yeah: )

Yeah mine cuts out every now and then too, esp when starting it up after its rested for a short period of time, ie not cooled down completely. Like you start it, about to take off, and it stops, try again, same thing. End up I just put on choke again for 10 seconds until the revs suddenly shoot up, and turn it off and then go. Seems to work, but really odd.
That sounds like it's running too lean, rather than too rich.

WanaGo

11th March 2005, 13:37

Mine has patches of no power, like only for a split second, then it recovers.
I rang 2 bike shops just before, and they were both willing to have a look (no surprises there). One said it could be all sorts of things, but narrowed it down when he heard it had only done 35000k.
Going to take it for a good ride on the weekend, and see how it acts then.

Vifferman - yeah my car was like that a while ago - problem is, the ZX9R dont have an ECU as such I dont think - older technology here. And the battery has been disconnected quite a bit lately with no changes.

Cheers
WanaGo

vifferman

11th March 2005, 13:48

Vifferman - yeah my car was like that a while ago - problem is, the ZX9R dont have an ECU as such I dont think - older technology here. And the battery has been disconnected quite a bit lately with no changes.
Wouldn't matter if it did have an ECU, unless it had an EFI unit similar to that on the VFR. It has a 'closed loop' mode that it employs for constant throttle and low rev running, where it runs ultra lean and monitors the zorst gases via two O2 sensors. In this mode, it stores the settings based on info picked up when the ECU has been reset, then the lazy bloody thing doesn't bother re-checking them again, assuming that nothing has altered significantly.

trev

11th March 2005, 15:06

The bike will run fine for weeks then suddenly ( esp. if at constant 100 k on motorway ) it will miss-backfire; miss-backfire half a dozen times then run O.K. for 500m or so then do it again & again etc.
Last time I didn't think I would make it home. Took it to Mt. Eden Motorcycles the next day with it missing like a bastard on the motorway ( O.K. off the m'way); Matthew jumped on & it didn't miss a beat. He took it down the motorway next day, took it home ( & he did -I checked my odometer & the bike had done 20+k) & the bloody thing never missed a beat.

Their feeling is I have a short somewhere & my extra weight ( 105kgs v Matthews 70kgs at a guess) sets it off.

Mark ( Mt. Eden M/Cycles) said the side stand sensor switches are known to play up & to try by-passing it. This switch cuts the ignition when you let the clutch out with the side stand down or if the side stand drops down while in gear.
When I looked at the bike prior to buying it there was a radar detector fitted which came on when the bike was started.The previous owner removed it. I've looked to see where it was wired into the loom as a potential shorting site but I cannot see where it was wired in.
I'm hoping its the side stand switch

WanaGo

14th March 2005, 22:01

After going for 2 long rides over the weekend, the bike hasnt improoved. It runs beautifully above 50k, just purrs along and has tons of power - as Slingshot will tell you. He took it for a good cain up and down a small town, ending up with the a local telling him off. We were testing out to see if we could hear a clunk between 1st and 2nd with him riding - anyway, the bike screems along no probs, its just town riding that is not that great. I had to do a bit of commuting today, and when getting back into town from the open road, it runs especially bad, gurgling along with the odd splutter, every now and then a slight loss in power, and as soon as you blip the throttle, it takes off, but returns to its gurgling after that...

Going to check the air filter this weekend, along with the air ducts etc. If that fails, Ill probably take it in for a tuneup or a check...

Any more suggestions, let me know!

Cheers
WanaGo

WanaGo

15th March 2005, 20:25

Just been emailing the last owner, and he said the bike has different plugs in it to standard.
He said this after I asked about the running jerky and backfiring:

As for backfiring thats a new one....it only came out of the workshop....what you could try is replace the plugs with the original ones according to the workshop manual....The new ones in it are higher burning plug...as i was told that NZ fuel is not good and to use a higher plug....That will make a big difference in the backfiring! so ive been told.

What do people make of this? Would wrong/hotter burning plugs make this sort of problem? Would it also make it backfire more? Would it also be correct abuot the statement about NZ fuel?
I really dont know the facts about spark plugs to know if this sounds correct or not. Feedback?

Cheers

WanaGo

15th March 2005, 22:11

Just been thinking and looknig at my haynes manual. It mentions my bike has Electronic, Digital Advance ignition system.
What I was thinking, was - I could be very wrong - but if my bike has been raced in the past, is it possible that the ingition has been advanced to increase the performance for racing, and in return it has made it run a little ruff at low speeds?
Like - just thinking along these lines, what could possibly have been done to the engine/ignition system/fuel system, to increase performance for racing, that could possibly decrease performance for slower riding?

any ideas?

Cheers
WanaGo

chic 'n' charge

27th December 2005, 17:51

Hiya - I've got the 94 model ZX9R and I had trouble with it once on a trip north where I had moments when it died completely when travelling at any speed - the answer was the fuel pump!!! first place I would look. What happens is ...... the fuel pump turns on once fuel gets down to half a tank right - when my fuel pump went to turn on it was already on - hence it blew the fuse over and over again. Apparently this is a known issue with these models - (unbeknown to me however).

What fuel do you run? If you think it has been altered for racing try putting high octane fuel in it and check results! might find it has different settings than standard road stuff eh....

I find I can't run it in top gear below like 70km's without it starting to chug like a tractor, I normally ride around in either 2nd or 3rd in a 50km area, depends on traffic.

Good luck.

Chipster

27th December 2005, 20:25

My '99 C2 had a recall about2months from new, was carb icing. Apparently there was insuffucient warming coming from a water feed to prevent the carbs freezing. This was not only a problem on cold days but also on really high humidity - like now! Because it was a recall it was fixed for free, however I had heard that it was only a problem on the C2s, so it might not affect yours. Worth a look though.

Chipster

27th December 2005, 20:28

Infact, the more I think about it, another minor problem I had was random misfiring, that turned out to be the ignition cutout that's fitted to the side stand to stop you pulling away while the bike's stand is down. It took me ages to work it out, but managed without resorting to dealer services. It was as simple as a scrub with some CRC and a toothbrush.