Engine Has Low Power

Air in fuel system.
Poor fuel quality.
Fuel tank empty or fuel tank vent blocked.
Fuel control lever not obtaining full throttle.
Clogged or defective fuel filter.
Restricted, blocked or leaking fuel injection or supply lines.
Incorrect timing or defective fuel injection pump.
Restricted or damaged fuel injector.
Restricted or damaged air filter.
Low manifold pressure.
Injection sequence does not correspond with firing order.
Low or uneven engine compression.