Suzuki 2 Strokes

I feel the need to rebuild the petcock on my GT500. It does not have the correct petcock though, however my question is, what size is the 'O' ring on the diaphragm and can a new diaphragm be had? So far all the 'rebuild' kits have every part but those two.

Robert - when you figure it out, let me know as I'll have the same problem with mine when I go to rebuild it. HVC Cycle has kits that have the small o-ring, but no diaphragms. Alternatively, on the GT750, the small o-ring on the diaphragm stopper happens to be about the same size as one of the oil pump base o-rings on a GT750. I'll let you know how long it lasts.

if memeory serves me correctly, i believe i ordered a new one for my T500 from bikebandit, but that was about 5yrs ago,

I don't know if the T500 petcock has the same mounting as the GT550, but I am using a manual petcock for a XS650 Yammy, bolted right up, and seals to the tank the same as the original.