ZX9R Rough running

**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

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.

**WanaGo** · 11th March 2005, 10:48

Originally Posted by trev

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.

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.

I thought it wouldn't make much difference to back pressure/mixture, but obviously it did.

)

Originally Posted by WanaGo

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

Originally Posted by WanaGo

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.

**Mattyc** · 9th January 2006, 08:19

Originally Posted by WanaGo

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.

mine is a 95 zx9r, it got a clunk between 1st and second, aparently its normal.