ZX10R engine stutter

[demondave]

Hi Guys I have owend a ZX10R for a couple of months now and it seems to have a kind of stutter when im not accelerating or decelerating. Its particularly bad about the 4 - 5 rpm range at 100kmish, ie im just cruising along in a high gear. it doesnt seem to do it when the revs are higher. my thoughts are, it may be the petrol im using? i use 95 octane from shell? maybe a higher octane could be better for a sports bike like this. or its my throttle control??
Also when i put it into 1st gear from neutral it clucnks really loud and moves the whole bike. is this normal? i checked the chain and its not too loose so i dont think thats the prob.
any feed back qould be great!

[Tony.OK]

Most fuel injected bikes are tuned from the factory to meet certain emission and noise regulations which are normally measured at around the 5k rpm mark, it is possible if dynoed you'd see a dip in the fuel curve which can cause the snatchyness with certain throttle applications. Newer bikes have gotten better but none are perfect when it comes to fuelling.
A power commander can help alot, especially when mapped on the dyno.
Has your bike got an aftermarket exhaust or air filters, they can amplify any fuelling probs too.
The 1st gear thing sounds pretty normal for a large bike.
Another thing you could try is to change your gearing via sprocket size, that'll change the rev range where you sit at open road cruising speed.

[Gremlin]

Also when i put it into 1st gear from neutral it clucnks really loud and moves the whole bike. is this normal?

The kawasakis are well known for their truck like gearboxes. They also feel like shit when you are puttering around town. However, get it into the country/track (where they belong) load the box with some revs etc, and she should slip like melted butter through the gears (I still own one).

Re stutter... need more information on mods to the bike etc. I had my bike dyno tuned on 95 shell... so not specifically a problem I wouldn't think.

[demondave]

Yeah i have an after market Yoshimira exhaust on it. Can you explain what the dyno does?

[Tony.OK]

Yeah i have an after market Yoshimira exhaust on it. Can you explain what the dyno does?

It measures HP/torque and air/fuel ratios basically, with a Power Commander you can get it tuned for optimum air fuel ratio's throughout the rev range which in turn smoothes out any fuelling glitches, and can give you some more hp too.

[martybabe]

I recently switched to Shell V power on my Gsx 1400 and whilst it goes like a frickin rocket at high revs, it definitely causes a little surging at around town speeds, not a huge deal but a kind of on off throttle feel as you describe. So, I'd experiment with different octane fuels to start with, it may be all that's needed and it's certainly the cheapest option.

As for the first gear clunk, yeah a lot of bikes do it, some much worse than others, especially when the oil is cold first thing. Experiment a little and you can normally minimize it. One of my Harley's banged in with such force it could be measured on the Richter scale. Holding the clutch in for thirty seconds before starting off completely cured it.I think that was a dry clutch but still worth a try. Another one, if we're talking in normal use here, is to blip the throttle slightly before selecting first, in other words give it a few revs quickly, and as the revs die disengage clutch and snick it in gear.

Good luck.

[avgas]

if you dont mind me asking demondave what did you own before - i'm assuming a standard 250/4 (but have been wrong before).
All big bore bikes with open pipes burble the pipe as you decelerate from 8K down to 3K. Something about the engine dumping waste fuel straight (as you have closed the throttle).
I love that sound.

[demondave]

Haha yeah avgas, you are right, how did you guess?? It dos the "burbling" as you said but thats not the problem, it doesnt really bother me. The problem is when im not accelerating or deccelerating (as i trying to keep at the same speed) the engine starts to stutter. I might start trying out different fuels as martybabe suggested, however, im using 95 at the mo, that only leaves 98 to experiment with doesnt it? would you reccomened using 91?!?!?!?!?!?!

[demondave]

thanks for the feedback martybabe, will definately try the clutch and rev thing

[martybabe]

thanks for the feedback martybabe, will definitely try the clutch and rev thing

Your welcome mate, hope it works, theres nearly always a way to work round a clunky box, unless of course It's not a generic thing and there is actually something wrong with it but I doubt that.

Back to the fuel, I don't see why you can't try 91 octane up but I'm quite prepared to be overruled on that by more knowledgeable types.

My old girl runs well on 91, no perceptible difference on 95, only V power makes a noticeable difference, not so much that I'd seek out a Shell station though, just a treat now and again.

[sugilite:Me]

Yeah i have an after market Yoshimira exhaust on it. Can you explain what the dyno does?

this is prob the cause, because they try and run those bikes as lean as possible for emission reasons...with the after market exhaust, it prob goes a bridge to far fueling wise at low revs...a power commander with dyno tune would do wonders me thinks.

[Gremlin]

would you reccomened using 91?!?!?!?!?!?!

I would avoid 91 with the 10's compression.

Has anything else been changed on the bike, is the exhaust a full system, or just a slip on?

[Max Preload]

I recently switched to Shell V power on my Gsx 1400 and whilst it goes like a frickin rocket at high revs, it definitely causes a little surging at around town speeds, not a huge deal but a kind of on off throttle feel as you describe.

I second that. I'm pretty much an exclusive BP Ultimate user in my bike but thought I'd give a tank of V-Power a crack and noticed the exact same thing - light throttle/low rpm surge. I changed back to BP Ultimate and it disappeared again. It was very minor though (I doubt most people would notice it but I'm a pedantic prick) so I'm fairly sure it's not what the first poster is experiencing.

[martybabe]

I second that. (I doubt most people would notice it but I'm a pedantic prick) .

Hhahaha, me too, I'm soo fookin fussy. Nice to get a second opinion, cheers.

Superb avatar by the way.

[demondave]

Nothing else that would affect the bike engine running wise has been changed, yep the exhaust is just a slip on. If my trialling with different octance fuels has no positive outcome, how do i go about getting a power commander with dyno tune? any ideas of costs?