Just a question - The low pressure fuel pumps on my 1997 ox66 250 Yamaha - What makes them work?<br />Is it pressure/vacum from the engine ports?<br />I just replaced them and it makes me nuts if I can't figure out how womething works.
Take it apart, and you will see that it is a simple little gizmo with two diaphragms and four little reeds which allow the fuel to pass only in one direction, as the pulses from the crank housing move the inner workings of the thing. i do not understand why the mfrs have not gone to an electric pump,, Gutshot in NC
hey gutshot, the simple answer to that is there is no need, the diaphragm pump is a robust well designed piece of equipment. newer fuel injected units still utilise this pump as a pickup pump coupled with an electric pump.
