How to tighten mower deck. How tight should a mower deck belt be? Apparently a 14.5 hp engine will work just as well as a 21hp in a riding mower.
How Tight Should A Mower Deck Belt Be Belt Poster
The belt’s deflection is measured. To test whether or not you need to tighten your deck belt, turn the mower on, maneuver it to uncut grass, and disengage the blades of your mower. You shouldn’t be able to twist the belt more than. (the short answer) a mower belt needs to be tested for the energy required to deflect over a set distance.