Hi,i have problem with rattling sound on my 2005 xtx.Sound become louder when i speed up in 5th gear from 110km/h to 150-160km/h.Also i notice,that engine has lack of power and slow acceleration.I check valve clearence and its ok.
Does anyone know what would be a problem or what shoud i look at firs?Thx

Does it rattle in 4th gear?

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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

It rattle in all gears,special in 5th.Its sound like someone is hammering the engine.
I have drive friends 05 and 08 xtx and they didnt make that sounds,also i dont get it why i cant pass 160km/h and reaching that speed is very hard,even down hill.

I would be taking your bike to a mechanic before something big happens, OK I see you are a mechanic, you should have the skills to diagnose the knock?

I would not ride the bike if the motor had a knock you could be causing further damage.

__________________
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

Its hard to locate exact point where sound comes,cause its transferring all over the engine,but most probably comes from the front side of the engine head(right behind water radiator).

There is one more thing,when i check valve clearence i notice that right exhaust and right intake valves were on low side of factory specification(intake 0.09mm and exhaust 0.16mm) and left exhaust and left intake valves were on high side of specification or even more,but i didnt bother to reset valves cause were not so much out of specification(intake 0.15mm and exhaust 0.20mm).Is it possible that cam bearing is damaged.

The cam has a ball bearing on each end if they were damaged you would hear a roar from the cyl head. you should try to keep the valve clerance's as close as possable whether you run them loose or tight (both ex the same & both inlet the same) check the valve and ign timing & A/F ratio (fuel map). failing that i would pull the head off and check in side for damage before it goes BANG! it will cost you lots then.

Maybe this ?
http://www.wilddog.za.net/forum/index.php?topic=73721.0

I will tray that.

Could it be camshaft (timing) chain tensioner? Cam chain too loose and making rattling sound.