I just changed the blades on my Yardman Lawn Tractor. And now the lever that engages the blades will not stay over. I pull the lever left to right and it usually stays in place and the baldes stay engaged.
I removed the deck to change the blades. It seems simple enough, I only had to un loop one end of one belt. And remove the cable that attaches to the blade brake. When I put deck back on I looped the belt over the pull I unlooped it from and reattached the small cable to the blade brake. There does not seem to be any way to make a mistake. Yet the lever will not stay in place and engaged. If I pull the lever to the right the blades do engage, but will not stay engaged because as soon as I let go of the level it snaps back to the left.. ANY IDEAS?

You have the belt routed wrong.