sr250 diaphram question

[chunglez]

my yamaha sr250 (1989) has been running like shit, i found a hole in the diaphram in the fuel control valve. not sure if thats the technical name for it, but its the valve that can be switched between primary, reserve or on.
Ive been told that its an expensive part and was wondering if any one knew of an alternative cheaper replacment part from another model bike.
Im a student so cheaper is better!!

[hayd3n]

im pretty sure you shouldbe able to get a factory it one should be cheap as !!! they still stock parts for the sr they are a very reliable bike