2006 YZ450F Chain Tension

I just moved from a Honda CRF450 to a 06 YZ450F. The Yamaha book says to run the chain tension between 1.9 inches and 2.3 inches. Honda recommends between 1 inch and 1.5 inches for the CRF450. What is everyone running on a late model YZ450F? 1.9 to 2.3 seems like an awful lot of slack. Everyone at the track keeps telling me to tighten it, but I tell them I am running it at the recommeded spec. If there is already a thread on this, I apologize, but the searching was disabled.



Yea, there are alot of threads on that subject. I think it is too loose so I tighten it just a bit. Make sure you check the chain tension by rotating the rear wheel one revolution. Good choice red to blue!

Do what the manual tell you to do. I run mine at about 2-2.1 inches, and never had any issues with it. The Yamaha isn't a Honda.

Sit on the bike until the swingarm is level and see how tight the chain is. The manual is most likely correct but this method will ease your mind if you are worried. Too tight is not good, stretches the chain and loads bearings on jump landings.

Do what the manual tell you to do. I run mine at about 2-2.1 inches, and never had any issues with it. The Yamaha isn't a Honda.


check out the manual all the specs are in there....

I run my chain at 2 inches slack. If you tighten it much more than that when your rear suspension compresses, the chain will tighten up too much. Plus if you keep your chain tighter than spec, it will stretch twice as quick.

The manual is correct, 1.9" is the minimum. To go tighter than that is to invite a broken rear hub. With the rear suspension fully extended, it does look as if it's looser than it should be, but it's the right amount of slack for the exact reason that mxracer206 brought up; there needs to be a minimum of 5/16" actual free slack at the point where the centers of both sprockets a nd the swing arm are aligned.

I use the 3 finger rule at the rear of the top chain slider - my fingers measure approx 2.1 inches

If you go too loose - you will get wear on your frame - above the chain slider

To find the perfect adjustment you should remove the shock and lift the rear wheel up and down through the complete travel. when you find the position that the chain is tightest adjust the proper amount of free play. Then reassemble the bike and check your slack. That would be the optimum adjustment for your chain. The only variance would be if you were riding in muddy conditions, then you would need to give the chain more slack.

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