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Discussion Starter #1
I've searched and searched but can't find any related issues to answer my question. just got my 2015 two weeks ago and the first 1K miles has been great but now at 1400 miles it feels terrible when getting on and off the throttle. Not sure how to explain it other than it feels like a rear diff with a ton of gear lash. The transition from off throttle to acceleration is no longer smooth like it used to be. Makes me nervous getting on and off the throttle near corners. The throttle cables seem to be adjusted properly. Thought they do seem to loosen up later in the ride. Chain has no more that 1.25" slack. The chain was pretty tight, in my opinion, when I bought it new. How tight is too tight? Manual only says NO MORE THAN 1-1.25" slack. Coming off Throttle by wire belt drive bike so chains are new to me.
 

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Hi, my gen4 is very smooth

have you taken out all the play at the throttle grip?

Chains are often too tight from the dealer/factory, don't know why

chain should be adjusted while on the side-stand, I like mine fairly loose, aim for about 10/15mm play when you're sat on the bike

throttle cable shouldn't really loosen up when riding, might be something going on there (?)
 

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I've searched and searched but can't find any related issues to answer my question. just got my 2015 two weeks ago and the first 1K miles has been great but now at 1400 miles it feels terrible when getting on and off the throttle. Not sure how to explain it other than it feels like a rear diff with a ton of gear lash. The transition from off throttle to acceleration is no longer smooth like it used to be. Makes me nervous getting on and off the throttle near corners. The throttle cables seem to be adjusted properly. Thought they do seem to loosen up later in the ride. Chain has no more that 1.25" slack. The chain was pretty tight, in my opinion, when I bought it new. How tight is too tight? Manual only says NO MORE THAN 1-1.25" slack. Coming off Throttle by wire belt drive bike so chains are new to me.
This happens with every new bike. I have owned dozens of new motorcycles and the chain and driveline just "opens up" a little after a thousand or so miles. Part of it is obviously the throttle cables, part is the chain slack, but also the cush drive dampers in the rear wheel loosen up just a tad and you can feel that.

Also, riding techniques have changed since EFI was introduced.

No longer can we keep the throttle closed to the very bottom of the turn at max lean and then crack it open like we could with a well-set up bank of CV carbs. You must train yourself to at least get the slack out of the throttle cables BEFORE the bottom of the turn (max lean) so you are back on the gas - albeit the slightest amount - to prevent that driveline shock that upsets the bike.

It's a differnt technique; took me a couple of years to relearn how to control the throttle on these new high-powered, EFI bikes but there it is.

One last thing, the Kawasaki exhaust backpressure valve is operated by cables and they do get loose. This also has an effect on throttle pickup.

To recap:

-chain gets loose
-cush drive loosens up
-throttle cables get loose
-exhaust backpressure valve cables get loose

Because of the cush drive it will never be quite as tight as when new no matter what you do.
 

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The latest generation of fuel injected bikes have what's called "off throttle fuel cut". This is where the injectors are turned off when the throttle is closed for emissions and fuel consumption reasons. It's a known issue with the harshness when getting back on the throttle. It's been talked about numerous times on here. The only way to cure the behavior (aside from driveline lash) is through an ECU flash. Once that's done, the response when picking up the throttle becomes much smoother.
 
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Ditto what Skydork said. My throttle felt much, much smoother after the throttle cut was disabled.
 

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Hi, my gen4 is very smooth

have you taken out all the play at the throttle grip?

Chains are often too tight from the dealer/factory, don't know why

chain should be adjusted while on the side-stand, I like mine fairly loose, aim for about 10/15mm play when you're sat on the bike

throttle cable shouldn't really loosen up when riding, might be something going on there (?)
You didn't mention if you had the reflash, I did not have that done, bike is stock all the way. I think the throttle pickup is more than acceptably smooth.

Like any other major modification, go through the stuff you can fix and adjust first before doing a reflash. You optimize all that, then do the flash. Also you should give yourself time to adjust to the bike. Big power, light weight, needs a smooth throttle hand.

Too many guys think they have a problem that they can fix tossing money at the bike when just getting the setup right and learning to ride the bike will cure it.

This same thing is just as true with road bicycles; a difference of just a millimeter in seat height, stem distance, and so on makes a big difference in control and comfort and efficiency.

Take some time to learn about your bike and get it broken in and adjusted. It takes a few thousand miles, minimum.
 

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Discussion Starter #7
Thanks for all the helpful responses. Glad I'm not just imagining this. I am getting flashed and tuned by Nels at 2WDW tomorrow so I'll talk to him about this. And I'll snug up the chain a bit.
 

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Nothing makes me feel the normal whatever. Take it to the dealer and have tech evaluate. The odd feeling off the throttle is not right to me.
 

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The latest generation of fuel injected bikes have what's called "off throttle fuel cut". This is where the injectors are turned off when the throttle is closed for emissions and fuel consumption reasons. It's a known issue with the harshness when getting back on the throttle. It's been talked about numerous times on here. The only way to cure the behavior (aside from driveline lash) is through an ECU flash. Once that's done, the response when picking up the throttle becomes much smoother.
True, but OP stated issue did not surface until 1400 miles were on the bike. If ECU has not changed - or does not have a "break-in" program that changes at a certain mileage - then the problems are likely mechanical.

I don't doubt that further improvements can be made with the flash though, but mine is very good stock, throttle cables at near-zero slack, adjusted exhaust valve cables, chain slack where it should be.
 

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True, but OP stated issue did not surface until 1400 miles were on the bike.
Perhaps the OP just took a little bit to get comfortable and gain confidence on the bike to start giving it some :dontknow:

I know that the fuel cut off was a major thing I noticed right away on my gen 4, it's much harsher than other bikes I've owned. I don't know if all fuel injected bikes have it or not but I never had a real issue with it before. Before I got the Woolich I checked the things you mentioned and it helped a little but for me it was still unacceptably harsh. The flash addressed it and now all is good, not to mention the other benefits the flash had too.
 

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Perhaps the OP just took a little bit to get comfortable and gain confidence on the bike to start giving it some :dontknow:
That's entirely possible. No way of knowing much of anything on the Internet.

If the flash helps that much and I already like my bike the way it is, might just have to do it.
 

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Discussion Starter #12
It is entirely possible that I have just realized this or that I have just started to become comfortable enough that I'm riding differently. I am have a really hard time being smooth around corners right now. I could see the Cush drive breaking in. My Harley had Cush drive also though and it never had a break in period. Has felt the same in the last 30k. I'm not getting an ecu flash for this issue. I ordered a cat delete last week and getting it tuned just to open everything up and get it running like it should. I have yet to own a bike that couldn't benefit from a good tune. I don't think the chain is too loose. It was very tight when I picked it up. It has broken in to a about an inch, no more than the 1.25 max in the serf manual. Should it be tighter? It does seem like the throttle cable loosens up during the day. I Realize that doesn't make a lot of sense but it does. Maybe I should adjust some of the free play out of the throttle cable? Thanks everyone.
 

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I'm not getting an ecu flash for this issue.
This issue was the sole reason I went with a reflash. The other benefits of the reflash are nice too, but this one particular issue is reason enough.

This issue cannot be tuned out using a Power Commander, Bazzaz, etc. The reflash is the only way to do it.

I run zero slack in my throttle cable as well. It's much easier to modulate smoothly with zero slack. Just be cognizant of the fact that the throttle can actuate slightly when maneuvering with the bars near full lock and the cable is tensioned by it. It won't do it a lot, but some minor increase in RPM as result is possible.

1-1.5" of chain slack is good. Better to be on the looser side of the adjustment than the tighter side.

The cush drive is nothing more than rubber blocks in the wheel hub. There's no break-in with them and they should be zero-lash. If there's play in the sprocket carrier and the wheel hub, then the cush drive is damaged. It's really there to help cushion the rear wheel on downshifting/deceleration than it is in the acceleration phase, but it works both ways.

My opinion is that you're just more sensitive to the throttle issue now that you've exited the break-in period and are riding the bike properly.
 

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Discussion Starter #14
This issue was the sole reason I went with a reflash. The other benefits of the reflash are nice too, but this one particular issue is reason enough.

This issue cannot be tuned out using a Power Commander, Bazzaz, etc. The reflash is the only way to do it.

I run zero slack in my throttle cable as well. It's much easier to modulate smoothly with zero slack. Just be cognizant of the fact that the throttle can actuate slightly when maneuvering with the bars near full lock and the cable is tensioned by it. It won't do it a lot, but some minor increase in RPM as result is possible.

1-1.5" of chain slack is good. Better to be on the looser side of the adjustment than the tighter side.

The cush drive is nothing more than rubber blocks in the wheel hub. There's no break-in with them and they should be zero-lash. If there's play in the sprocket carrier and the wheel hub, then the cush drive is damaged. It's really there to help cushion the rear wheel on downshifting/deceleration than it is in the acceleration phase, but it works both ways.

My opinion is that you're just more sensitive to the throttle issue now that you've exited the break-in period and are riding the bike properly.
Thanks SkyDork. I've just been tuned by Nels and I thought this bike was crazy before. It's ridiculous now. Runs fantastic and about 70 percent of that issue is gone now and I'm certain the rest of it was already there. Nels loosened my chain and took more slack out of the throttle cable. Very happy now. Very scared of it now too. But I guess that's probably a good thing for now.
 

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You didn't mention if you had the reflash, I did not have that done, bike is stock all the way. I think the throttle pickup is more than acceptably smooth.
My bike is UK (Euro) spec and is bone stock, no flash. I like it best that way :smile2:
 

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My bike is UK (Euro) spec and is bone stock, no flash. I like it best that way :smile2:
You don't need the flash, you already have it if it's EU-spec, lol

Some US bikes are getting flashed to EU-spec (if stock) to get full power.
 

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Some guys over here are getting their UK spec bikes flashed as well, probably to get some extra features, adjust for decat, eliminate the 02 sensor etc. My bike runs smooth as butter, so I think best left alone :smile2:
 

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Some guys over here are getting their UK spec bikes flashed as well, probably to get some extra features, adjust for decat, eliminate the 02 sensor etc. My bike runs smooth as butter, so I think best left alone :smile2:
No doubt there are a few things that could be massaged, especially if you change intake or exhaust.
 
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