Bike had been sitting for years. I put a battery in and attempted to start it but bad gas. I drained it put some new gas in ran ok but started leaking at quick connect. I took it apart changed air filter, connector, fuel pump, fuel filters, hoses and tank seal. Now It starts but spits, backfire and wont idle. The former owner told me it had a stage 1 kit put in when he bought it new. any advice is needed