Clunky Throttle

[Guest Johnnyx]

NC750s

 

Hi folks! maybe a strange one this.. but I find opening the throttle from closed, at low-ish speeds in 2nd always comes in with a 'clunk' ... I am careful with the throttle, to be as smooth as I can.. but this is a wee bit annoying because I'm already thinking of coming out the corner smoothly.. but now also thinking about not clunking my chain! Only 5000 miles on the bike so be surprised if anything wrong.. Anyone else experience this phenomenon?

 

Other than that - pleased to report bike is awesome! ha!

 

Cheers guys!

[suffolk58 2,286]

Just a guess John, but are you riding in "Drive".

If so, try "Sport" for a while and see if that feels better.

 

That's assuming you are talking about a DCT bike!

Edited July 15, 2015 by suffolk58

[Guest Johnnyx]

ah sorry not to mention! its manual ... so at the moment I can only blame myself!

[Guest mrgrumpy2]

fuel injection kicking in?

[prr 153]

I have the same "issue". It is even more noticeable when you are using the engine breaking and then go back to gas at 2000rpm. It was the same on my previous bike too (Duke 200). KTM did firmware upgrade to reduce the sudden power back but didn't fix it fully. I was told by the dealer the reason behind is that during engine breaking the ECU fully stops the fuel supply. As you start adding gas at a time the ECU detects the throttle is no longer fully released and starts back the fuel supply. At that time the engine suddenly becomes alive and kicks. 

[noj 365]

Worn cushdrive??

[trisaki 2,029]

Try it with more revs nc's run and feel better 3000 revs onwards

[pjm 6,041]

I know what he means. On a tight U turn I regularly drive through as I try to gently open up there is nothing and then a surge. I wonder if adjusting the slack on the throttle cable might help. Don't quite see how keeping it above 3000 rpm would work

[embee 7,288]

As pjm says above, I was going to suggest adjusting the throttle cable slack to the minimum you're happy with, usually  the less slack the better for smooth "tip-in" control. As long as there is a trace of free play between the cables when the throttle is closed it'll be OK, the way the cable cams are designed the slack increases as soon as you start to open the throttle so the cables can't "fight" each other.

 

 Also try doing the ECU reset procedure, it's free and can't hurt, and it is just possible it may help.

[Guest bonekicker]

Throttle cable slack could be the problem --try adjusting --it is easy to do-- as Murray says keep the slack to the minimum--- please let us know how you get on   

[Tex 36,817]

NC750s

 

Hi folks! maybe a strange one this.. but I find opening the throttle from closed, at low-ish speeds in 2nd always comes in with a 'clunk'

 

If it only happens in 2nd then it's unlikely to be any sort of fuel problem surely?

 

John, you say 2nd gear. Is it always in that gear? And never in any other?

[Guest John_Minus_600]

I've noticed this (or something similar) in 2nd on the manual 700s, usually running up to roundabouts where no stop required but revs are low. I tend to feather the clutch a little to take the edge off.

 

The clunk I get is from the chain tensioning under the change of load on the transmission. 

 

I'd think its normal for a twin at low revs to 'chug on' like this. Its certainly noting i'm worried about personally, just a characteristic of the bike at low revs.

[prr 153]

Throttle slack won't help - the engine is "dead" and once the throttle off sensor is deactivated it suddenly becomes back alive. You can't stop it. I use two ways to overcome it. First one is the clutch. Simply let it slide and the kick is greatly reduced. The other way was suggested above - high revs. In such case even there is a bit of fuel injected the engine still drags back instead of pulling so the transition is way smoother. Chain tensioning has much less of effect. 

[pjm 6,041]

Bit difficult to slip the clutch on the DCT box.

[prr 153]

Hi Peter, I suppose you are right. One of the reasons I didn't order DCT

[Guest Johnnyx]

awesome .. thanks for the replies! 

 

Feathering the clutch is my aim just now - glad to hear other folk do that as well... and yeah, I understand better.. this is a twin, so maybe power delivery is clunkier, and I have also read about the fuel injection stopping whilst throttle off.  I did own a fuel injected Suzuki DL650 a few years ago, that though seemed fine for the most part.

 

I did say this was a 2nd gear issue, maybe I could extend it to third.. but seems a less of a clunk/jirk in 3rd, as if there is better damping.. I haven't noticed any issues in 4th/5th/6th, but perhaps thats because the engine is under a different load or something.. haha .. thats me trying to apply logic.. never a good idea.

 

From the replies above I feel this is normal-ish.. so maybe should just keep trying to work around it!

 

..and I will check the Throttle slack Michael

Edited July 16, 2015 by Johnnyx

[Guest Arthritic Toe]

Yeah I think over the time I've had the bike I've subconsciously introduced a quick flick on the clutch at this point to make the transition from engine braking to acceleration smoother.

[CFB 4,602]

If you do decide to adjust the throttle cable, be aware that on full lock, the cable are tighter than when the bars are straight so check there is no rise in revs at full lock.

[Guest Peter]

I experience the same issue- say on a roundabout or U turn - it seems to be impossible to roll the throttle on at low speeds and not go through a dead spot before the power surges. I thought it might be a rider issue, but now that I have more experience I think, like you guys, it is the nature of the bike. Sometimes I can be smooth, but if I'm at very low speed I need to use the clutch. My dealer says it is just how the bike is. Not a satisfying response, but that's the only one I have had. Now Tyre pressures - don't get me started.See other topic.

[Guest Peter]

Just made the adjustment and is better

[Guest Peter]

The throttle cable adjustment has made a lot of difference to the low speed snatch, and to riding in general - gear changes are smoother now as well. Thanks all for the comments, and for the adjustment advice.

[Guest Johnnyx]

ooh! the throttle adjustment Peter? - I've been using the bike a lot these past days and not had a chance to fiddle with the adjusters... if you find it seems to work I'll have to bump it up my to-do list!