Husqvarna manufactures zero-turn lawn mowers, riding mowers, lawn tractors and push mowers. All of the seated mowers and some push mower models are equipped with mower blade engagement systems that are separate from the engine start system. However, it's possible to lose engine power when blades are engaged. A thorough inspection of your mower's start system and conditions can help you find the problem.
Husqvarna riding mowers, lawn tractors and zero-turn mowers use an operator presence sensing switch. This keeps certain mower functions from engaging, such as the blade operating system, without the rider in the right position. If you leave the seat and the blade is engaged, the mower will turn off. You also have to keep your body fully centered on the seat when operating in rough conditions. Otherwise the mower will hesitate or shut off.
Keep your Husqvarna mower clean underneath it or its performance can suffer. Whenever the blade is engaged, it rotates on a crankshaft to cut the grass. But if there is interference in this rotation, the engine can overload and shut off or lose power. Check the crankshaft connection to see if it rotates freely. Inspect the connecting hardware for damage or rust. The blade should be free of dirt, grass or debris as well.
If the grass is too high, your Husqvarna mower may have difficulty cutting it. The blade will try to power through, which results in engine power loss. The same can happen if the grass is average height but on a slope beyond the manual's recommendations for operation. If you are using a Husqvarna push mower, try adjusting the wheels as necessary to cut high grass. Also inspect the grass for thatch or natural debris before cutting.
Engine oil provides lubrication, cleaning and cooling properties for Husqvarna mower engines. However, the oil cannot be above capacity in the engine. Any excess oil will spill from the crankcase into the combustion chamber. If the mower requires additional power such as during blade engagement, the presence of oil will hamper the fuel vapor combustion. Too much oil will also spill into the exhaust and clog it, thus restricting airflow for combustion.