hi everyone,
so i was chatting to a friend of mine about his bike and established that his petcock is playing up so recommended a rebuild kit, handy enough. when it arrived it had a square diaphragm instead of the round one in his petcock. so i got onto google and cant find any rebuilds for his one.

now from my research the fuel set up on the gs 500 is a mess, if you go WOT for any real distance it is starved of fuel and starts to die, so there are tutorials on drilling out wider fuel passages in the petcock.

www.beergarage.com/GSPetcock.aspx

so we were considering doing that when i showed him this tutorial, there was a break down of the parts and he seen the diaphragm spring and said his didnt have any?? he threw it all back together without it and its the same as before, dies after WOT and hesitant through the revs. (also speculating that a vacuum leak on that pipe would cause bad performance from one of the carbs)

so im thinking there has to be a better way of doing all this. is there a manual alternative to using the vacuum?

i was thinking of either removing the diaphragm fully or else cut it to be like a gasket, then "blank" the vacuum connection at both the carb and petcock.
and if this leads to over flowing of the carbs when sat up i was thinking of putting in a small 12v fuel solenoid working off the switched power coming off the ignition barrel.
( inc delivery off ebay – http://www.ebay.com/itm/12VDC-Water-…-/220975797346)

any suggestions as to if it will actually work, or any bolt on replacements that can be got for it?

appreciate it lads.