A ratchet gear is continuous linear or rotary motion in only one direction while preventing motion in the opposite direction. Ratchets are widely used in machinery and tools. Though something of a misnomer, “ratchet” is also often used to refer to ratcheting socket wrenches, a common tool with a ratcheting handle.
Then when it was running, the motor was spinning that part with the worm gear ate the teeth off that half-circle gear on the kickstart spindle.
I can’t imagine any other way that gear could get hosed that badly.
Double Helical Gear
A special type of gear which is a side to side (not face to face) combination of two helical gears of opposite hands.
From the top the helical grooves of this gear looks like letter V. Unlike helical gears they do not produce an additional axial load.