Hi, I have a 2008 Tenere and recently replaced the exhaust with a single aftermarket can, my standard air filter was replaced by Yamaha with a DNA stage two filter with the DNA stage one insert. I am concerned that my engine might be running to lean. I have installed my own DIY KEVMOD (thanks kev), but instead I have measured the resistance to drop the temp by more or less 5 � 6 degrees and soldered a 470 ohm resistor inline with the airtemp sensor. I have also removed the stage one insert from the DNA filter and now running stage two. Although the bike is running fine I am still concerned that I might be causing engine damage by running to lean? I will post some pics of my sparkplug colour later.

Firstly welcome to the foum mate.

470 ohms resistance is not enough resistance for a XTZ fuel mod with your mods, you need 3000 to 5000 ohms on a Z with those mods to get the A/F ratio in a safe zone. Also do the AIS mod to stop the popping back in the exhaust.

My current fuel mod for a XTZ runs a 10K ohm variable resistor. The main forums main web page can't be update at the moment, I will update it in the near future when the problem has been sorted.

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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

Thanks for the info kev, think I will put back the DNA restrictor to be save, I have measured the airtemp sensor at around 27 degrees C�s and the resistance was about 1.8k ohm, when I increased the temp to 36 degrees C�s it did go down to about 1.2 or 1.3k ohm�s. Will I be able to determine if the fuel/air ratio is in the right range by looking at the sparkplug? I have done the AIS mod and it did helped a lot with the backfiring - thanks again for all the info.

I measured the A/F ratio using a Wide Band Power Commander so no quess work was done, connect a 5K resistor in series & you will be safe.

Checking the plug with unleaded fuels these days is a bit of guess work.

__________________
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

Thanks will do that.

I have connected a 4k7 resistor in series with the airtemp sensor. Running great, but my fuel consumption went down from about 20km/litre to 15km/litre. Any suggestions?