We have a few now.

XTX & XTR

2004 to late 2005, part number on ECU 5VK-8591A-00, very hard to fix the surging. Twin spark ECU. Fuel device does help with the surging. Cuts out at random. Adjusting the CO will help at part throttle with the surgingMy fuel mod or PCV/PCIII does help with the surging but will not cure it with this ECU.



Late 2005 to 2006, part number on ECU 5VK-8591A-01, almost surge free, runs perfect with a PCIII & custom fuel map or Kev's fuel mod, adjusting the CO will help at part throttle with the surging. 01 ECU used under warranty to replace the 00 ECU on 2004/2005 models, when customers complained about surging & cutting out. Twin spark ECU. Can also use other fuelling device with good results. Also cust out at random at times but better than the 00 ECU



Mid 2006, introduction of a remapped 00 ECU with white paint dot on rear of ECU, part number on ECU 5VK-8591A-00. This was a parts only supply & was not fitted in production, parts catalogue part number is 90891-30032 to be fitted to pre 2006 models. Not bad for surging, better then a 00 ECU by far. Twin spark ECU. Was also used for complaints under warranty from customers with the 00 ECU 04/05 models. Yamaha are now suppling this as a 5VK-8591A-01 when using this part number 90891-30032. YOU CAN NOW BUY THIS PART AS A REPLACEMENT ECU AT HALF THE NORMAL COST. Can be mapped well with a custom made fuel map & Power Commander, or Kev's fueling device.




2007 to 2008 ECU, part number on ECU 5VK-8591A-10, introduction of the O2 sensor with single spark, altered ignition timing & an increase in idle speed. Bike surges a lot, the only way to fix this is with a fuelling device + Kev's new 2012 O2 eliminator mod or Dyno Jet O2 Optimizer mod. Adjusting the CO up makes the bike cut out at times & does not help with the surging.




2009 to present, ECU part number 5VK-8591A-11. Still shows signs of surging at part throttle, surging fixed with a Power Commander & Kev's new O2 eliminator mod . Adjusting the CO up makes the bike cut out at times & does not help with the surging. I found unplugging the O2 sensor & leaving it disconnected made the bike run to rich. The old resistor type plug in O2 eliminators do not work. Recommend fitting Kev"s 2012 O2 controller or Dynojets O2 Optimizer

I have learned of some new functions between the 01 & 11 ECU on the dyno. Yamaha have removed the over run shut off function on the 11 ECU.
What this means is when you are riding on the freeway & shut off the throttle the 00 & 01 ECU cuts off the fuelling completely, the 11 ECU does not cut the fuelling any more, it leans the A/F ratio out to 14:1. This feature offers a smoothers uptake of the throttle when you open the throttle again.



XTZ

2008>2011, ECU part number 11D8591A-00. Very little reports of surging. Can runs Kev's fuel mod or a power commander as a fuel mod with filters & cans.Can fit Kev's 2012 O2 controller or DynoJets O2 Optimizer to completely fit the surging.




You can not swap ECU from bike to bike, once the ECU has been coded to a bike it stays with that bike for life.

You can swap the whole lock set, with keys including ignition switch & immobilizer from bike to bike. 2004 to 2006 or 2007 to 2010

2004 to 2006 ECU's can't be fitted to 2007 to 2011 XT's as they have a different amount of pin locations & different size plugs.

You can fit a 2004/2006 ECU & complete wiring loom to a 2007/2011 XT's & visa versa.

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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

09/ 2012
Update new O2 Controller mod plug & Play

http://www.xt660.com/showthread.php?t=14746&page=17




18/12/2010

I now have a mod that will reduce the surging for the 2007 to present XT660X/R's with O2 sensor, it's a new O2 controller that turns off the O2 sensor completely (Closed Loop circuit) this allows us to remap the fuelling using a Power Commander across the whole fuel map without the intervention of the closed loop circuit.

All the details are here. Kev's 2010 New O2 Mod for XTX & XTR's
http://www.xt660.com/showthread.php?t=14746

They can be bought from EBay or via PM to me.


Been doing some testing with the 5VK-8591A-11 ECU today which is fitted to the XTX & XTR 2009 models onwards.

This is what the surge looks like on a Air/Fuel ratio logger with the standard yamaha fuel map, no fuelling device fitted. I have a Dynojet Wideband O2 data logger that shows & logs the A/F ratio in real time. As you can see roughly ever 10 seconds at 10% throttle & 2500RPM, the bike switchs between rich & lean which is what the rider feels when it surges, this recording was taken while riding. It should be around the 13:1 mark for best HP/Torque & be constant not up & down all the time. I will remap the ECU using my PCIII in this range & post the results soon.

http://www.youtube.com/watch?v=ZwTfuwZZ848

The ideal A/F Ratio for our bikes is around 13:2.

I am working with different set ups to try & find the best solutionfor this ECU.

http://www.youtube.com/watch?v=K5ubpdHu3uY

__________________
Click here to join the XT Supporter's scheme

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