[Shop-talk] 2 stroke vs 4 stroke

[Wayne]

On 3/6/2013 10:41 PM, Doug Braun wrote:
> I suspect that any engine that is designed to operate in a fixed position
> with gravity fuel feed (e.g. lawn mower) will be easier to start that an
> engine that has to run when moved around (e.g. chainsaw), because of the
> carb design.

2-S Power Equipment, like saws or trimmers, has a "pumper carb". A 
little rubber diaphragm & check valve use engine vacuum pulses to suck 
fuel from the tank and keep the carb constantly full, and pump any 
excess back to the tank. Roll around things like mowers or bikes appear 
to use regular gravity fed float bowls.

Had to rebuild the carb' on the Ryobi last summer. Was surprisingly 
easy! (and I usually trash any carb I touch) $7 kit, clean it up, dial 
two screws and runnin' like new  :)

-Wayne