About 2 weeks ago my bike started to stumble 3.5K-5.5K in first & second primarily. Thought it was an electrical short.... Removed my PCV, WB2, Alarm, quickshifter, and changed the plugs.... Still stumbling. Swapped out ECU's, still stumbling. Then I thought it had to be a bad injector, maybe clogged, or debris in line..... Well I ran 4 tanks of gas through the bike this week, 2 with Techtron, 1 with redline and one with BG 44K (that stuff fixes anything usually). Nothing.... Still stumbling. The 14R supposedly gets its speed reading off the KTRC sensors (I was told anyway), not the countershaft like Gen 1 14's.... That's why the speedo is correct even with different gearing.
Well Thanks to Shane on the other forum, he said his does the same thing but if he puts the stock sprocket on it goes away... Put on the original sprocket tonight & its fixed.... SO, if you have a sprocket on it that is different than stock and your bike is stumbling or surging in first or second gear when just cruising with very little throttle..... put the stock sprocket back on if you want to get rid of it. If anyone knows or figures out a way to defeat this please post it, several people have this issue now and a solution would be greatly appreciated.

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BTW, weird thing is some bikes ahve different gearing and are not doing it.... Any ideas?

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Seno, every once in a great while I seem to think mine is doing it with stock gearing. just a slight enough to make me think I'm twitching the throttle just a bit.

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All of my issues started when I took a stock ECU from a brand new bike and plugged it into my bike (while mine was out being reflashed....). As soon as I plugged it in my bike started stuttering 3.5K-5.5K in the lower gears.... First I thought it was coincidence, my bike is modded to hell and figured it was a bad tank of gas or something... Well something happened and it was a nightmare to diagnose.... I am glad Shane posted the same issue on the other forum or else my bike would have been at LI Kawasaki later today. My dealer was going to rip apart the fuel system... What a waste of time and money that would have been.
To test it out, go in 2nd gear at 5K RPM.... Just maintain that speed (about 45-50) and see if it bucks & stutters. Hopefully not. Good Luck

* Last updated by: seno on 8/13/2012 @ 5:12 AM *

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Thank god. I thought i was crazy. I had a 16 up front and a 43 in the rear. It was fine. Last week went back to the stock front bam it bucks with a lil throttle in second around four grand. I called steve at brocks and he was dumb founded by the problem. Well after reading this i'll go back to the stock rear and now. Of course i threw away the stock rear so hopefully the vortex fourty two sprocket will work like the stock one. Im getting tiredqof all the problems with this bikes ecu.

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By the way i only have the stock ecu. But my flies are removed.

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Try putting your secondaries back in.That might correct it.

* Last updated by: Grn14 on 8/13/2012 @ 12:20 PM *

"several people have this issue now and a solution would be greatly appreciated"...okay....do some detective work then....what is the COMMON denominator(s) for 'several guys' that have this problem.

My bike ran great stock.Perfect.I bought the Brock's Full ti single CT.PCV...with a Brock's REVISED street map(first one 'bucked' as you say(secondaries removed as well).But only just off idle...at minimal speeds.Otherwise...ran great.Installed the Guhl flashed ECU...his first flash.Bike ran great.Rode er like that for several thousand miles.Recently installed a 43 rear sprocket.Bike runs great....no problems.Speedo is dead on...it WAS 3 mph off with the stock gearing.

Okay...so what is different here?When did the stumble with my bike appear?I switched ecu's at one point...I have a stock new factory ECU...for backup.Bike runs fine with either...except the Guhl's is more responsive...and gets better fuel mileage.Other than that...she runs fine with either.Smoothness is there...

Smokin added a very possible scenario with these bikes...the ECU MAY have to relearn the stock parameters again...or....correct for any changes as long as they're within the factory parameters...it may take some riding to do that.IDK....That's ONE possibility.You know the CAN unit is processing thousands of signals at any given time.It MAY need to take a bit of time to correlate the 'new' info with the ECU....who knows?I don't.But maybe?

It doesn't sound plausible to me that a ONE TOOTH change would cause a bike like this to perform enginewise so radically different.Mine is doing fine....so how is mine so different than the others who are having this issue?That I don't get.If my bucking deal was corrected with a revised fueling map....I wonder why so many are saying.."it can't be that"...That's what I don't get.Gearing?It wouldn't be much different(one tooth) than the bike 'having a traction problem"...that is...wheel speed difference.The programmed ECU parameter for the KTRC...I can't see how it would be being exceeded by a one tooth difference(causing the motor to restrict).And in fact....with mine...apparently it isn't.KTRC on '1'.Haven't tried any other settings with this 43 on there...I will though...just to see what she does.

IMO...it's not the gearing...it's something else.My guess...fueling...somehow.PCV...Wideband...whatever...something other than gearing.Those draggers aren't getting this...right?and they're changing gearing like crazy...right?You can only change so many things....you guys say.."I went back to stock gearing and it went away"...okay...I certainly can't say it didn't.There IS some guesswork going on here...lots of it actually.Saying.."somebody told me"...or..."I heard"...okay...fine...maybe.That doesn't equate to FACTS necessarily.Who one these forums actually KNOWS what the systems on the new bike are really capable of?What they do between each other.NOBODY.Not for sure.

But this driveability thing...mine was corrected...simply.Been good ever since.THE ONLY issue I began to hav over time...after installing all this stuff...was the backfire was beginning to appear.I checked the Pair block-off mod...the hose was indeed slipping loose from the blocked airbox hole.I blocked(again) the hose(this time IN the hose)(and checked the airbox block cap)...problem solved...no more roughness with that...no backfires...nothing.

I know this is gonna sound possibly insulting...I don't mean it that way...BUT....the left side airbox port IS the one these guys are blocking,yes?If they're not...it won't have very good driveabilty...and the gearing 'programs'(fueling,TPS) won't work right.(assuming the exhaust and such has been modified,remapped)...this came from Brock himself.I trust that to be true.

* Last updated by: Grn14 on 8/13/2012 @ 12:58 PM *

Think it may be TPS related.... Unfortunately I am pretty busy until Thursday night, if anyone else getting the "issue" has a chance to check TPS voltage please do it and post up results.

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Hey seno another thing we will see is if it is the sprocket itself. See i threw away my kawi rear sprocket a couple of months ago[didn't think i would ever use it again] so now i had to order the 42 tooth sprocket from vortex again. I hope to god this works,the ride home from work tonight was horrible. I had to quick shift out of 2nd gear in traffic or it would lunge[on off on off].It feels like to me anyway when you try to power wheelie with trc on and the moment the wheeel comes of the ground it starts to cut the power my killing the gas it feels like. Other then that though the bike is very smooth,its just at a certain rpm,the ecu keeps cutting the gas off and on. My theory is this i think the computer reads the wheel spin and when you have a diiferent sprocket just in the back it throws it off almost like the computer thinks your back tire is spinning and cuts the gas to get it to stop. But when i had the front sprocket down one also, the bike was perfect.

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I rode for 60 miles tonight and it was perfect.... BTW my TPS voltage at idle was low .61 (usable range was 63-65 according to manual). Right now I am done messing around with this thing, its smooth as silk and since I put Ivan's flash on it... well I am as happy as I can be with this... My only regret was the frustration associated with this the past couple of weeks. Keep us posted, but I am 100% sure the 42T sprocket will solve your stuttering ( It solved mine & Shane's).

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Do all riders with a 43 tooth sprocket suffer from the stumble?
Does it stumble in all gears or is it specific to 1-3?
Does the KRTC setting have any impact on the situation?

I'm wondering if the ECU is looking for a certain number of wheel revolutions for a given engine RPM range. With a larger rear sprocket the engine RPM's will be higher at any given vehicle speed. If the ECU senses high engine RPM and lower rear wheel RPM it may think the bike is slipping and is trying to remedy the discrepancy.

Just a thought...

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Do all riders with a 43 tooth sprocket suffer from the stumble?

Some do, some don't.... makes no sense to me

Does it stumble in all gears or is it specific to 1-3?

1-2 is most noticeable but you can feel it in the upper gears also

Does the KRTC setting have any impact on the situation?

No, no impact... Does not matter if KTRC is on or off

I'm wondering if the ECU is looking for a certain number of wheel revolutions for a given engine RPM range. With a larger rear sprocket the engine RPM's will be higher at any given vehicle speed. If the ECU senses high engine RPM and lower rear wheel RPM it may think the bike is slipping and is trying to remedy the discrepancy.

Yes but there is no more countershaft speed sensor, so where is it getting its setting from? On the 14R the KTRC works off the sensor mounted to the brake rotor. I agree with you 100% and the theory makes perfect sense, BUT where is it getting the signal from?

Notice the slots on the piece mounted to the rear rotor, there is one on the front also.... Regardless of what sprocket you put on the 14R, the wheels are still spinning at the same rate.

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Seno do have any way of checking your AFR when stumble occurs ???

I Can and Have made my bikes stumble in the AFR table while playing with gearing.

Reason was due to the load on the motor. Less load (46Rear) would send my AFR lean stumble. Go to 41R tooth load would increase and AFR go rich and bike would studder.

I had to play with map for the gear changes. U know less Load with more RPM puts TPS sensor in diff location, which in turn sends your fuel cell to the wrong location in the map,,,,, there for in comes stumble or studder. They are diff for rich or lean.

Gearing Change = Map will always be off it's perfect cell location and must be adjusted. This problem is compounded by letting her breath with full pipe ETC. Tuning these bikes in the bottom end is not Easy and can be a big turn off. I assume this why most tuners don't work on this area.

Spent 2 years studying this problem with 2010 Turbo 14. Nuts I know but smooth in my obsession and I don't stop until perfect.

Squash throttle to wide open and all is fine right ? It's only at 35-45 ? From what you have posted we can fix.

If this post sounds right post back I have a test for you to prove this for sure. If I can help in any way I will Cheers.

Seno read some of your other threads. Sounds like Ivan's fuel Map solved this issue. Glad to hear it worked out cheers.

Yup...I can't see why a one tooth gearing change would affect the KTRC...guess it could though?But Seno says 'on or off'...so I think that eliminates any KTRC involvement.I always thought it was fuelling(my symptoms were bottom end 'idling speeds')(parking lot stuff)...which WAS corrected with a remap)...but...

When my KTRC is OFF...it's off for all intents and purposes(I have to control the throttle to get maximum grip)(or stop a wheely;))...although Brock and some others said the bike has a 'fail safe' 'mode' to it in certain situations.I don't believe cruising at 3500..to 5K is one of those situations.If that wheel's spinning though...IDK...maybe.Sometimes the wheel spin on mine is VERY subtle.Someone pointed out here a while back...which I had totally forgotten about the KTRC...it isn't only reactive...it's also intuitive...it will activate under certain situations BEFORE there's a problem..just depends on what the ECU's comparing.(engine speed,wheel speed,and others).EVEN if it's actually turned off..as Brock confirmed.There's more to the electrics on this bike than people realize.This IS the most sophisticated KTRC Kawasaki has come out with so far.

* Last updated by: Grn14 on 8/15/2012 @ 2:39 PM *

Seno read some of your other threads. Sounds like Ivan's fuel Map solved this issue. Glad to hear it worked out cheers.

Ivan's ECU is great, BUT the sprocket change back to stock is what solved the problem. Maps do not effect this condition, I have Ivan's, Brock's, custom, and a few others and NONE of these stopped the stuttering... If you read over on Bikeland you will see several other people are coming forward with the same issue who have 0 mods.... It is a problem with "some" of the 14's when you change the gearing. FYI, this weekend Ivan will have a map for the Brock's CT pipe with his ECU.... Making one Saturday.

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There's more to the electrics on this bike than people realize. This IS the most sophisticated KTRC Kawasaki has come out with so far

Indeed you are correct... Just look at the safety mode... It took 2 months to find out there was a safety mode. There is more going on below the surface and it is frustrating until someone figures it out.... Funny thing is that only some of the 14's are doing it... My bike was PERFECT with a 43T sprocket... Until it started doing it... go figure.

* Last updated by: seno on 8/15/2012 @ 2:58 PM *

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FYI, this weekend Ivan will have a map for the Brock's CT pipe with his ECU.... Making one Saturday.

any chance you're going to put the offending sprocket back on and see if you and Ivan can get rid of the stumble?

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any chance you're going to put the offending sprocket back on and see if you and Ivan can get rid of the stumble?

Ivan & myself spent over 5 hours last weekend trying to figure this out and changed the plugs also. We ruled everything electronic out that were added onto the bike (PCV, WB2, Quickshifter, Alarm, Grounds, connectors, and various wires), his guess was fueling.... Well that was before I changed the sprocket and the problem disappeared. Looking at it now, it has to be an input from one of the sensors or something else buried in the ECU. Some people were suggesting that flashing the ECU had something to do with it but the fact is ALL ECU's are doing whether they are stock OR Flashed regardless who flashed it.

* Last updated by: seno on 8/15/2012 @ 3:14 PM *

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Ivan & myself spent over 5 hours last weekend trying to figure this out and changed the plugs also. We ruled everything electronic out

Wow, you guys are not giving up. Great info for all. Cheers Guys

his guess was fueling....

Mine was too. My test for this was placing lap top on top on tank, turn on cell tracer in pcv, watch and study the cell location at the stumble. Install diff gear and make note of the New cell tracer location, as it will be diff with more or less load on the motor. AFR working together with the fuel changes found & fixed my stumbles. Changed fuel settings in map to match new cell location and problem solved.

Ivan would have done this only in a much safer way. No danger of lap top hitting the pavement Lol.

Head scratcher 4 sure.

Could Ivan duplicate stumble on the Dyno ?

Looking at it now, it has to be an input from one of the sensors or something else buried in the ECU.

Will Don with Ivan be looking into ECU for hidden code ?

The problem is definetly a misfire.... I don't know if it is caused by fueling.

I can tell everyone that it does not respond to changes in the corresponding throttle position in the PC5 table... the 3 maps that Seno has are all different in those columns and the symptoms are the same... no better or worse with different values.

It kind of feels like when one of the cams are out of phase with the cam sensor (this bike doesn't have one) or the injectors are firing at the wrong time??

Once the throttle is moved past 10-15% the problem stops.... (ECU changes to TPS vs. rpm)

Maybe the change in gearing is causing the ECU to see something outside the parameters that it's supposed to.... on the other hand, why would they design a bike that won't allow gearing changes.... most likely a firmware glitch... someone needs to check if the 2013 ECU is the same part #.

Maybe it's simpler than all of this... It will eventually be figured out.

Ivan

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I know this is an old thread but anything new? Ivan and chance you have got this figured out? Roman, would the autotune solve the problem?

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I just installed a 43t rear sprocket and have the same stumbling problem at around 5000 rpm in 2nd gear. My bike is a 2014 ABS, stock except Yoshimura slip-ons.

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There is a good thread on the zx1441r board about this. This is just from what I read. I haven't changed mine.

IIRC the issue has to do with the ecu switching quickly between fuel or timing maps for the next closest gear because it thinks at a certain speed and throttle opening and rpm it should be in a certain gear map. with the sprocket changes it gets "confused" and jumps back and forth, causing a stumble. Don Guhl had a beta solution but on one persons bike it didn't solve the problem. I THINK that Lee Pritchard aka smokinzx14 said if you used ecu editing software (woolich) you could copy the same fueling maps into each gear and maybe it would fix it?

hopefully he will chime in. OR go read the other board. http://zx1441r.com/forum/viewtopic.php?f=9&t=1042