Cub Cadet MTD 90 Series - Manual (Page 15)

Introduction
9
Fuel
Gasolines currently on the market are not pure gasoline. Today’s fuels have alcohol and other additives in them to
reduce emissions. The fuel make up can vary seasonally and geographically.
Fuel with alcohol added to it is sometimes referred to as “oxygenated fuel”. The extra oxygen carried by the etha-
nol increases the oxidation of the fuel. This speeds up the process that causes the fuel to go bad.
Excessive alcohol in fuel creates a lot of problems for gasoline engines. One of the biggest problems is that alco-
hol attracts and holds water. This corrodes the metal components of the fuel system, especially the carburetor. Alco-
hol also does not produce as much heat as gasoline when burnt. This results in less power for the engine.
A 10% alcohol mix (E10) is acceptable for MTD engines. Anything higher than that will result in performance
issues.
NOTE: E85 and E20 fuels are not to be used in any MTD engines.
NOTE: Use clean, fresh fuel with a pump octane rating of 87 or greater.
• Stale or out-of-date fuel is the leading cause of hard starting issues.
• In areas that have high amounts of alcohol in their fuel, high octane fuel may improve engine performance
and startability.
Fuel filters
Dirty fuel can clog the carburetor and introduce abra-
sive materials into the engine. To help prevent that, MTD
engines are equipped with a fuel filter. The fuel filter is part
of the fuel tank nipple. See Figure 1.8.
Figure 1.8
fuel filter
Nipple