Murray rider mower. Drive belt broke. Purchased replacement belt. Do not have a diagram for installing the belt but put on one way and could not engage the clutch couldn't stop without killing the engine. It seems like there is only one other way to put the belt on with v in groove and flat against flat but then the belt seems too short as I cannot get it over the large pulley then. I need help. M

Boy, does that sound familiar. I hope you didn't do what I did. I went to an auto-parts store and got a belt that was "the right size" for a roto-tiller. Unfortunately, it wasn't the right type. It had slits on the inside of the belt. It did exactly what you described. I was able to get the project done, though. Getting the correct belt cured the problem. I'm not saying your problem is like mine, but there is a chance.

How might anyone really help without a model number?

The drive belt will go on tightly, are you locking the clutch / brake pedal down while attempting to install the belt? If not try that.