What Causes My Cub Cadet LT1050 Lawn Tractor to Slow Down After a While of Cutting Grass?

Cub cadet introduced the LT 1050 in 1986. It uses a Kohler twin cylinder gas engine that is rated at 23 horse power. The LT 1050 is classified as a lawn tractor and, at a weight of 548 lbs., it can accomplish most cutting and pulling tasks. The LT 1050 is equipped with a CVT transmission which allows infinitely variable forward and reverse speeds.

Cub Cadet makes a wide variety of lawn tractors.

Fuel Starvation

A dirty or clogged fuel filter can cause the tractor to lose power over time. A fuel-line that is routed too closely to a heat source can vapor lock. Vapor lock is when the fuel evaporates inside the fuel-line, due to excessive heat. Both of these conditions will rob the engine of fuel, resulting in low power output.

Spark Plug Fouling

If the engine is running in a rich condition, the spark plugs will foul and lose their spark intensity. A rich condition is when too much gasoline is entering the engine. The most likely cause of a rich condition is a choke that is not opening fully upon engine warm up. Another sign of a rich condition is black smoke from the exhaust.

Low Transmission Fluid

The transmission fluid on the LT1050 must always be kept at the full level. If the transmission is low on fluid it can slip when the tractor is hot or when it is under load. This will slow the tractor down. The transmission will sometimes make a whining noise when operated. This does not always indicate a low fluid level. Check the fluid level at the dipstick.

Clogged Air Filter

A clogged air filter will rob the engine of power. Without sufficient incoming air, the engine will struggle to breathe. This will cause the engine to expend extra effort in pulling the air through the air filter. This can also put the engine into a rich condition, resulting in other mechanical issues.

Slipping Drive Belt

The LT1050 uses a belt to drive its transmission. Under heavy use this belt has been known to slip on these models. A new drive belt will solve the problem. The transmission itself is not a serviceable unit.