xr400 rattle

[sport]

Hi. New to the xr400 and dirt bikes generally. Mine has a big rattle when riding along, not at idle or when revving stationary. Is this the chain on the slider (can I adjust out) or something else?
Ta

[stretchy]

Bit vague?

Put in on a center stand, make sure the chain is clear, start it and run it in gear; the chain should skip a little (but not a lot) and you'll be able to see(?) where the 'rattle' is coming from?

[sport]

Don't have a centre stand and rear paddock stand for my road bike doesn't fit.
One thing- the chain makes a lot of loud clicking when I push it round the garage, more than any road bikes I've had did- does this mean this could be the noise and should I tighten- is there a how to guide I can look at?
Ta

[Kes]

Check the chain for a tight spot .

[jasonbc]

Don't have a centre stand and rear paddock stand for my road bike doesn't fit.
One thing- the chain makes a lot of loud clicking when I push it round the garage, more than any road bikes I've had did- does this mean this could be the noise and should I tighten- is there a how to guide I can look at?
Ta

Put it up on beer crates or axle stands anything to get it of the deck, no hope of a paddock stand working. Chai tension could be the problem or tight spots, the guide for setting them up is normally stuck on the swing arm but that may have been worn off if not it is definatly in the handbook also check rear sprocket is square with front sprocket. AS for rattles mines has plenty need more info to help you though

[416cc]

Sounds like you have a few teeth missing from the front sprocket.

To test for correct chain tension either get a friend to sit on the bike and check for about 1" up and down movement on the bottom run.If it's too tight it will very quickly ruin your gearbox sprocket bearing.This will mean a complete engine strip to get to this part.

[sport]

Checked front sprocket and seems fine - no teeth missing and not hooked.

However, chain is VERY loose - I can push the bottom run up against the swing arm easily and the top run can be pulled up well over an inch!

So, what size socket do I need to undo the right side wheel nut- presumably once loosened, I tap the other side nut with a hammer to adjust?
Ta

[stretchy]

You should have 'Snail Cams' fiited to measure the adjustment. I run a very loose chain as recommended by my motorcross mates, a tight chain will wreck the gearbox and wear both sprockets. If in doubt fit new chain and sprockets

You dont use hammers on anything other than nails unless of course you bike is one! I hope it's not!

24mm I think..............