I have a 1991 Evinride XP 150 V6. The engine has been relatively well maintained. It runs strong and idles decently. I have been told by numerous people that I should remove the VRO system and just mix the oil with the gas. Can anyone tell me how I might know if it is on it's way out? Will I get a warning before it fails typically? What is involved in making the change? How much will it cost? THanks for the help.