You have to push down on the rear suspension to properly adjust your rear chain. When you push down on the suspension, you will notice the chain will get tighter and then looser as the suspension goes through it's travel. When the chain is at it's tightest point you should have about 3/4 of an inch of slack. It helps to have someone else push down or sit on the bike while you adjust the chain.
To measure it, just feel it with your hand at the middle of the chain. If the chain is too tight, it can break and damage your engine. It can also damage the engine by putting too much stress on the countershaft bearing.
PLEASE STOP ADDING INCORRECT INFORMATION TO MY POSTS!
That is not correct. :| It depends on the location of the swingarm pivot point in relation to the countershaft sprocket center point. Some bikes have the pivot point above the C/S sprocket, some are below and some are even. This puts the tightest point on the chain at different parts of the suspension stroke on different bikes. That is why it is important to compress the rear suspension and check for the tight spot.
In the service manual, Yamaha recommends putting the bike up on a stand with the rear wheel off of the ground and adjusting the chain to 1.6 to 2.0 inches. But using the tightest point method, you can be sure your chain isn't too tight.
I did not read what Eric Gorr says. I posted what the official Yamaha service manual says. :coocoo:
In regard to double checking your chain at the tightest point.
My information comes from 40+ years in the industry. From that experience, I know that not all bikes are the same when it comes to the placement of the swingarm pivot bolt in relation to the countershaft sprocket pivot point. That along with the location of chain rollers on most bikes will change where the chain is at the tightest point through the stroke.
On some bikes the chain becomes tight when you first push on the rear of the bike and then becomes looser as it bottoms out.
On some bikes the chain is loose at the top and gets tighter as the suspension bottoms out.
On some bikes the chain is loose at the top and gets tighter in the middle of the stroke and then loose again at the bottom of the stroke.
It all depends on the location of the pivot points. :bang:
By making a blanket statement like you did could cause someone to adjust their chain wrong and cause damage to their bike. Please, know what you are talking about before posting answers.
I realize you are only trying to help. But, you are not helping by posting wrong information and then wanting to argue about it if someone calls you on it. This only drags the quality of DRN down to the level of most internet sites. We pride ourselves on being a site where people can come and get accurate information and not have to put up with a bunch of kids arguing over who's right and who's wrong.
I am going to ask you one more time to stop adding incorrect information to my posts. If you would shut up for long enough, you might learn something. :|