What's the bolt hole spacing? Some are 44mm, others are 34. If you'd prefer a manual fuel valve, then get one that has the correct spacing. you can find them on eebbaayy. I've seen an oem Yamaha manual fuel valve for pretty cheap. in the $20-30 range. I think it's 34mm. maybe from a yamaha raptor, but I don't recall what years.
Stock vacuum petcock. My 81 650-csr is 34mm. I rebuilt mine with a K&L petcock kit, then several years after that I installed a K&L diaphragm kit. the oem parts may be available.
