Rattling sound
 

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?

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.

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.

Rattling sound
 

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.:icon_thumleft:

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

hi axt, have you checked your valve timing?. the pivot on the tensioner guide broke on mine and it may just explain the noise and lack of power. mine was out a tooth,
as i ride like an 'ould woman' i did not notice the power loss. checkout http://www.xt660.com/showthread.php?t=17351

I will pull out gearbox,but i have no time right now,you know job,wife,kids.....:009:

hi, the parts i was suggesting are veiwable from the generator side

Before stripping anything I would be diagnosing in what area the noise is coming from.

Known faults relating to noises in the 660 motor that I know of there might be others but these are the ones I have documented over the past 5 years. They failed for various reasons some were by abuse from not servicing.

1/ Lose tappets, many
2/ Main bearing failure, X2
3/ Big end failure, X1
4/ Cam chain guide plate broken, X1
5/ Decompression pin broken, X1
6/ Gearbox output shaft broken X2
7/ 3/4th gears broken, X2
8/ Worn piston & bore X2
9/ Clutch nut lose, X1
10/ Primary gear nut lose, X1
11/ Bent inlet valves, cotter broken, X1

I�m highlighting this thread since I have a rattling sound on my bike. It has ran 35000 K since march 2011 and I�ve done all service required on the bike and this sound appeared 3 weeks ago, I haven�t driven it since.