Lawn mower with deck lift system and/or pump lock-out system

1. A lawn mower comprising:

at least one cutting blade for cutting grass;

first and second drive wheels;

a cutter deck assembly and an engine deck, the engine deck supporting an engine that drives the at least one blade for cutting grass;

a handle control assembly for allowing an operator to steer the mower by controlling the speed and direction of the first and second drive wheels;

a deck lift system for raising together each of the cutter deck assembly, engine deck, and engine relative to a frame of the mower in changing a cutting height of the mower, wherein the deck lift system does not use chains to support the cutter deck assembly;

wherein the cutter deck assembly and engine deck are arranged so as to move together in relation to the frame in a rigid manner that causes there to be substantially no movement between the frame and the engine deck other than a controlled arc, resulting in one degree of freedom; and

an extension spring that resists extension, the extension spring having an axis that defines an angle of from about 0 to about 45 degrees with the vertical, and wherein the extension spring provides force to help lift the cutter deck assembly and engine deck when the deck lift system is used to raise the cutter deck assembly and engine deck.

2. The mower of claim 1 , wherein the spring is connected between, directly or indirectly, the frame of the mower and the cutter deck assembly.

3. The mower of claim 1 , wherein the axis of the spring defines an angle of from about 0 to 20 degrees with the vertical.