Hi guys,
I have a problem with surging/jerking my XT660Z r.v.09 53tkm.
Especially last 5 tkm is very strong (and I probably feel that it is increasing).
I've tried everything. Original state - added checked modified: new sprocket damper, new chain set, DNA stage 1 + 2, NGK iridium spark plug, KEV's fuel mod (try to sets from 3 to 9 clock) + O2 controller, blocked / unblocked AIS, deCAT exhaust. Checked fuel injector + fuel pump. Checked throttle body for leaking and everithing looks fine. TPS checked and set up according to the service manual (0,66V).
All of these modifications helped a little, but surging/jerking is still strong enough about 2500-3500 rpm.

When accelerating or braking, the bike runs normally. But in the city 50km/h 3-th gear it is enough to feel.

Engine disassembled 2 times.
1. 22tkm third gearwheel
2. 48tkm exchange drive axle bearing
could the problem be here? something wrong set / folded?

Please for any advice or idea where the problem might be.

W.

As discussed in your PM hopefully someone can help out an swap an 02 sensor with your so you can eliminate it, and to confirm you have disconnected that chain oiler & fitted the vacuum pipe back as standard?

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Mods that I have done to my XTX's

My 04 XTX
Stage 1 & 2 DNA filters / Kev fuel mod / snorkel mod / Drilled air box mod / Engine breather mod / Fork Spacer mod / 15w fork oil /
[
My 07 XTX
Raptor 700 cylinder 102mm / Modified Crank Case to take a 105mm Raptor Cylinder / 11:1 102mm JE Raptor piston / Stage 1 Raptor Hot Cam / Ported head / Colder Spark Plug / +2mm Throttle body / DNA stage 1 & 2 filters / Modified Air Box / Snorkel removed / Worry Brothers stage 2 filter cover / 6mm & 8mm Bolts Replaced with Titanium Bolts / Recovered seat in Black / O2 Eliminator /

My 09 XTX
59HP at the rear wheel / Stage 2 Raptor Hot Cam / DNA stage 3 Air Box / Carbon Can Exhausts / Modified Exhaust Link Pipes / PCIII With Custom Fuel Map / Wideband Commander O2 Data logger / LCD100 Dyno Jet display & fuel adjuster / 2500 OHM HT lead instead of a 10K OHM XT lead / Extra Coolant Cooler / Protaper Fat Bars / Tail Tidy With LED Tail Light / OKE Protection Knobs / LED indicators / AIS blocked / Modified rear sprocket rubbers / Rear Foot Pegs removed / 09 ECU With 02 Sensor Changed To A 06 ECU / Complete wiring harnes Changed from 09 to 04 / Home made LED resistor flasher / Hole drilled in the fuel tank filler neck to allow quicker filling / Modified Bar End Weights / Progressive front fork springs, 15W fork oil, forks lowered 25mm, used XTR rear links lowering the rear 20mm, rear spring one click stiffer / Changed front & rear guards from blue to black / 47T rear sprocket / Speedo Healer V4.0 / Kev throttle cam mod / Throttle grip mod / The new 2010 O2 sensor mod is out, works a treat, The new 2012 O2 Controller is out, PM me for details

Now ride a 2018 MT09SP ABS + TCS

My KTM 990 SMR Mod book. http://www.ktmsmt.com/viewtopic.php?f=13&t=4946

Hi Kev,
thank you very much for your advice.

I disconnect Scottoiler (put a new hose between sensor and throttle body due to leaks) but unfortunately without change.
At the end of this week my friend lends me O2 sensor. But now engine warwing light doesn´t show any error.
So I'll try it and give info.

Thank you very much.

W.

New finds after testing:
when i use original air filter and snorkel, my Ten goes beautifully smooth, that's great, almost no surging - (I must to focus on it to feel it), but engine is not so playful, rather lazy ☹

when i use DNA Stage 1+2, bike goes better, accelerates faster, engine is more flexible, but Ten starts surging from 2,500 to 4,000 rpm, (not as strong as before, but still feel enough) ☹
Fuel mod set from 3 to 8, best setting according to spark plug color = 6

Anyone have any idea why DNA Stage 1 + 2 Ten starts surging?

Did you confirm the O2 sensor was ok?..
DNA's will obviusly allow more air flow which will alter the fuel/air mixyure..Im assuming that 'something' is not setup to allow for this change.

I forgot to mention that I put new rubber between throttle body and engine (cracked) and I changed O2 sensor.