So ran my Argo with 23 hp Briggs engine this winter ice fishing, at the end of each day it went into my heated shop till next trip. I changed oil this spring and notice the oil came out chocolate colored. I let the engine run while loading and make sure it is warmed up before driving, some trips were 1/2 to 3/4 mile and drove at 10mph or less because I was never in a hurry, this should have warmed the oil up and burned any moisture I thought . Should I just keep a eye on the oil or how can I stop this. Had same problem with a Polaris ATV I owned.