XR400 help

Hey!

I bought my '01 xr400 2 weeks ago. I love the bike, but on friday as I was riding home from work.

I noticed a rather loud clicking sound from the engine.

The noise can be heard when turning the engine with the kick.

I thought that this sound probably had been there for some time.

And had increased in strenght over these 2 weeks, once you hear a noise you "REALLY" hear it.

My first guess was that it was the valves, but it were'nt. They where very little adjustment needed to get them within the tolerance.

And yes the auto decomp mechanism were'nt holding the rhs exhaust valve.

So I took off the cylinder head cover and inspected the rocker arms etc. Everything there is fine the same with the cam axle.

But I do wonder how much slack there should be on the auto decomp mechanism. I mean this might be alot too loose.

I'm able to move them quite alot (3-4mm).

Like this.

cam_marked.JPG

It generally feels way too loose. But this might be the way it should be.

Any pointers are welcome. Don't want to spend a lot of money on a bike I just bought...

Edit: Can it be that the cam chain is too loose?

Its hard to diagnose a "clicking sound" over the internet, it could be anything. The auto decomp does cut in at very low revs with the XR and if u have the idle set too low, it was will cut in making a "clicking" noise. Other than that, check your valve clearances and that the cam chain wasnt loose although if it is loose it makes more of a metallic ratling noise.

Hope this helps,

Mark.

The noise disappears at about 2-2500 rpm's.

The engine also feels a little funny at low rpm's.

Kinda like it's missing the punch. The exhaust also seems abit sluggish at low rpm.

did anything ever come of this? mine is making a similar sound at idle. i was going to tear into it and check the valve adjustment and timing chain tension this weekend (before i go riding again!)

Yes mine is doing the same thing too Damn It!

Im not sure what it is as of yet. It only does it at ldle, but that clacking comes and goes. When its stone cold it does not do it, when its warming up it starts, it comes and goes, then when it heats up more it does heaps, then after a little while it comes and goes again.

Its got me buggered. God, I hope its not the cam lobes, I only just bought it!

HXR400 - Did you ever figure out the cause of your clicking??? I've got something really similar going on with my xr4. It starts as the bike is warming up and seems to come and go. I'm running out of ideas (cam chain is my next try at fixing it.)

Yes mine is doing the same thing too Damn It!

Im not sure what it is as of yet. It only does it at ldle, but that clacking comes and goes. When its stone cold it does not do it, when its warming up it starts, it comes and goes, then when it heats up more it does heaps, then after a little while it comes and goes again.

Its got me buggered. God, I hope its not the cam lobes, I only just bought it!

HXR400 - Did you ever figure out the cause of your clicking??? I've got something really similar going on with my xr4. It starts as the bike is warming up and seems to come and go. I'm running out of ideas (cam chain is my next try at fixing it.)

Yes mine is doing the same thing too Damn It!

Im not sure what it is as of yet. It only does it at ldle, but that clacking comes and goes. When its stone cold it does not do it, when its warming up it starts, it comes and goes, then when it heats up more it does heaps, then after a little while it comes and goes again.

Its got me buggered. God, I hope its not the cam lobes, I only just bought it!

Yep, I did find out what that problem was & it wasnt until recently either, not until a couple of days before I sold it!

Dont worry its very simple, the noise is just the manual decompression system. Nothing serious.

You know the manual decompression leaver under the clutch? Well follow the cable down to the Cylinder head rocker box. The problem is the return spring for the manual decomp cable/linkage has stretched allowing the linkage to to vibrate. The Spring is not holding the linkage in the completly off position.

The clacking sound you hear is the manual decomp leavers inside the rocker box tapping on the rocker leavers.

That all make sense?

So all you need to do is replace that spring with a new or stronger one & your fixed!

So there you go! I hope that solves your problem!

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