I am a new owner of a 06 450F. I'm trying to adjust the chain and when I set it to the book(or I hope it is!), it seems too tight when I sit on the bike.

What is the correct slack with the bike on a stand. Book seems to measure from swingarm to bottom of chain. I'm use to just measuring free play!

Any advice?


Thanks Pops

The best way to check, imo, is to take off the shock so you can run the swingarm through its total travel. That way you can tighten the chain till it starts to bind, while going through the travel of the rear wheel, then back it off a little. You obviously only have to do it once then you know exactly how much slack you can run.

Man thats souds like alot of work-i just reach over the seat grab the swing arm and give a mighty tug have a friend eye ball the sprocket, the swing arm pivot and axle-when they line up viola you got the tightest part of your rear suspension travel in relation to the chain. Granted i am 6 foot 6 230lbs but even with my monster shock spring i can do it. But i can tell you my quick referance is 3 fingers right beind the chain slider on top of the swing arm and the top ginger should not fit under the chain but line up with a pin in the chain. You need to pull the chain up taught while you slide your fingers under it to check it. I have noticed this bike likes a tighter chain than most i have owned-usually putting three fingers under the chain at the end of the slider is a good rule of thumb{unless it is a ktm!} but on a kx 450 you get a lot of chain slap at the setting. To recap if you can put 3 fingers under it it is too loose and its gonna make some racket and you will see where it slaps the sub frame. Remember to turn the rear wheel and ck the chain in mopre than one spot in will wear unevenly and keep in mind a little too loose is still better than a little too tight and if you hear it making some racket tighten is a little more and recheck.

that's all too much work. While bike is on stand just measure from on top of swing arm chain guide to bottom of chain while pulling it up - adjust to 40mm, perfect every time (as stated in yzf manual).

easiest way to do it is turn the adjusters until the chain goes slightly tight then find the tightest section of the chain by rotating the rear wheel and pulling upward on the chain. Once you have found this place two fingers vertically between the swing arm(by the top chain guide/runner) and the chain.
If two fingers fit in without feeling tight - your chain is at the correct tension. Make sure that you adjust both sides so it tracks correctly otherwise you will have early chain and sprocket wear.

Later Chill

When i put two fingers on top of the chain slider at the back, my chain was a little too tight. It's not like i took my bike all apart just to find the perfect chain tension. When i greased my bearings for the first time i checked out the perfect clearance while the shock was off. Two fingers is a little tight. When i raised the wheel with the shock off it had a slight snug spot. Two and a half fingers on top of the chain guide at the back is about right. May be a little less. What can i say i'm a perfectionist. That's why every one has me work on their bike.

Maybe my fingers are just bigger than yours :lol:

Could be. I got some big meat hooks though.

between 25 and 35 mm slack at the longest point of travel

i do like the kawi manual says... 52 mm from end of chain guide to the center of the pins in the chain... works great no chain slap or binding... i do this while its on the side stand... as i found doing it on the center supported stand causes it to end up binding / too tight.