WR450 strange noise

[DR650Bandit]

My other adventure bike 2008 WR450 started making a strange noise on my last ride. ill try and explain as best as possible. bike has 6000km.
- noise just "started" at the beginning of the day, it has not been a gradual increase
- occurs under acceleration (and possibly deceleration, cant remember) and sounds like two bits of cutlery clanging and tanging together. its not a knock at the door sound, its very metallic.
- no loss of power, performance or an inability to start
- bike had not been ridden for a couple of months but did have new fuel put in it.


Now keep in mind, I havnt pulled it apart yet, as I already have two DR650's in pieces in my shed and want to get them back together first. It is NOT chain slap, I know what that sounds like, and mine doesn't make any chain slap anyway (fixed that problem once and for all)

since I have not lost any performance im not thinking valves or cam chain as nothing is different other than this new noise.

I have heard of clutches in wr's making wierd noises but dont know much about it. Anyone else had a similar noise or thoughts?

[jjrider]

Does the noise change or stop when pulling in the clutch?
Does it sound like it's coming from the top or bottom of the engine?
Tinny sounds could be from a broken bearing retainer or something like that or could be a valve issue that just hasn't gotten bad enough to notice power loss yet.
I'd thoroughly listen to find its location, then take covers off, may be something simple.

[DR650Bandit]

yeah that might be a project for today. thanks

[jjrider]

Just a thought, you said you had to put gas in it and the noise is ainly under acceleration, is it good gas with high enough octane rating? as in pinging from bad fuel, aka, detonation. Just throwing out an idea.

[DR650Bandit]

i doubt it. same fuel as I always use. I did get it from a different fuel station. maybe... I have got the top off and had a look at the timing chain. It's "tight" as in its neat on the teeth, but it has enough give that I can move it up and down with my hand between the cams. I dont really know how tight the chain should be? Im thinking tighter - as my DR650 is tighter than this.

[jjrider]

There usually will be a bit of give, just should be limited. is there a chain cover that it could be hitting though I would think it's something that would have gradually started making noise. Take out the tensioner and make sure it is working properly.

[DR650Bandit]

Mechanic tells me it is most likely a big end bearing failure or a crack under the piston. Iv taken the engine out of the frame and will begin pulling it apart. drained the oil and checked filter, not one bit of metal filing to speak of. Probably the cleanest oil iv ever seen come out of a bike.. ever! lets see what happens