I have a 18.5 HP Craftsman Lawn Tractor, model # 917.274811. It starts fine but the mower won't engage. The attachment clutch lever seems to have the same tension, and the drive belt seems fine. I've looked and can't see any obstructions. Any ideas?

It is a simple mechanism, clean the deck and levers WELL and see if idler (tensioner) is moving. The answer is there somewhere.

Don

Remove the deck, clean, inspect, and lube where needed.

I had this problem and fixed it. I cleaned well and oiled all appropriate parts.

Don's advice is sound. I would also check that the engagement cable is moving freely when the handle is moved. Make sure both cable ends are attached. Clean cable well and manually move cable to make it move freely.

I had this happen to me. The tractor ran fine but no mower engagement. Blades were unimpaired, belt seemed to rotate fine. But, it turned out that the belt had slipped off one of the pulleys and this was luckily and easy fix. Hope this helps, Good Luck.