Thanks for the input. I have an automotive degree so I know my way around motors pretty well and have raced and rebuilt several 2 stroke dirt bikes, but never an oil injected engine. I thought the oil injection system is pretty convenient especially for long rides but I do see the need for running a block off plate and premix only just incase the the pump takes a turn for the worst. I mean do these things just go bad or what? I bought some new oil lines a the auto parts store to replace them because the old ones were brittle. The last time the thing was even in the water was in 2004 according to the sticker on the side of it. The motor sounds strong, it starts right up and has great throttle response (when the starter engages haha, but my rebuild kit for it just came in today so I am going to do that this weekend). A local professional jet ski rider that runs the shop I got the jet pump assembly from said those old 650's like mine were pretty much bullet proof as long as the oil injection pump doesn't go out; is that true? One more question, on my ktm dirt bike I ran anywhere from 32:1 to 50:1 oil/gas ratio what should it be for a pwc with premix? Thanks for all the info., I really appreciate it!