Chain came off r70 riding mower how do i put it back on

Ok there is three sprockets one on the transmission a guide in the middle and onle on your back axle. take a wrench and loosen up the middle sprocket. slide it all the way back untill the chain is snug or tight. tighten up your bolt and it should notice it drives faster and thats how you keep it from falling off. hope it works for you

All chains have a master link installed that links the 2 ends of the chain together. See this link: http://static.howstuffworks.com/gif/how-to-repair-a-bicycle-3.jpg

-Find this link in your chain.
-Then remove the clip and slide the link out of the chain on one side.
-Re-route the chain over the sprockets.
-Connect the two ends of the chain together by sliding the master link through the end of the chain.
-Install the plate and clip on the master link.
-Tighten / adjust the chain so that there is about 3/8 inch vertical travel in the chain mid span

If there is no adjuster for the chian and the sprockets are some what worn, you may have to remove a link from the chain by driving out one "chain link" by removing one pin and barrel with a mini punch and installing a "Half Link"

http://t0.gstatic.com/images?q=tbn:Kj9glHLE1mjvBM:http://www.bikepartsplace.com/images/small/31186210.jpg

This should help you install your chain. Just note that if the sprocket teeth are quite pointed that is a
sign of long term use of a lack of lubrication. A chain lubricant is usually a very heavy grade oil 90 or 130 wt gear oil. You can use WD40 to losen the chain but I would recommend keeping the chain lubricated at all times to prevent unnesessary sprocket and chain wear.

Thanks for using FixYa.

Kelly