ok I bought this sled cheap.... its a 2000 800 rmk that the owner dropped a 02 600 non ves motor in it. everything is 800 except the engine itself. it had bad bog on bottom end. I re-jetted the 40mm carbs and that helped tremendously. but still has slight bog after the bog it gitty-ups real good. took it to my local sled shop and they told me I can't run the 600 without changing everything else? They claim i'll smoke the motor in no time cause the timing is different and exhaust is different, they are the original 800 parts. is this the case or are they filling me up with a bunch of technical b.s. that a person would ever notice. it has 800 slp twin pipes. gimme your input please.