loose chain. need help adjusting

i recently bought a 99 WR400. this is my first bike so i dont know much about them. the chain is super loose like it sits on the swing arm. is this normal for a WR and if its not how can i adjust it?



I don't have the specs for your bike, but my 2005 WR450F specs call for about 2" minimum sag, measured as follows: put the bike up on a stand, so the rear wheel is off the ground. Then grab the chain towards the front of the swingarm and measure how far you can move it up and down. Yes, 2" is a lot; and yes, it does sag onto the top of the swingarm when in normal riding position. That's why there is a long rubber strip on the front of your swingarm.

Good luck,


this is a regular issue

many people have opted to use a small amount of silicon sealant( roof and gutter type) under the chain slider for two reasons. about 8-10mm thick

1 the chain can chew into the swing arm if the slider wears through without being noticed ( ive think i read that it had chewed to the extent the swingarm started to crack?? not sure)

2 often wr people have mentioned the chain knocking against the swing arm and the silicon acts as a shock absorber under the slider and quietens it down. this is often caused when 'lugging' or using the low down torque part of the rev range.

as for tension, be very careful not to over tighten the chain and then go off a jump as when the suspension compresses, the chain tightens and can have terrible consequences.

make sure after you have tightenend it that you put your weight on the seat and and compress the rear as far as you can and check there is still some slack. manual will have more technical info i guess.

dude you need a manual fast. Take the time to learn it. I read mine at the dinner table sometimes.

hey thanks everyone for the help. your right man i really need a manual. i'm going to order one today

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