blasty

i have a 1998 tigershark 770l and when i bought it it had no compression on the front cylender, so i took it apart and found that the ringes were just stuck in the piston, the cylender was fine, so i bought a new piston& rings and installed it (without diognosing the problem) and it worked fine for about 2 or 3 houres till the next day when i went to use it wouldent start, so i pulls out my compression tester and low and behold nothing on the same cylender again, so i take it apart and find the rings again stuck and the cylinder is well scratched so im wondering what may be the cause to my problem could it be the oil injector or mabey the settings on the carbs or is there a common problem with these mecheans i dont know of, i should have mixes the gas instead i guess, but im wondering if there somthing else that might cause this on that same cyl.