Well I've heard quite a few ways from quite a few people... here are a few I've heard. Please chime in because I'm trying to find the best thing to do! (1) Winter: Drain gas, change oil. Spring: Change oil again (2) Winter: Drain Gas. Spring: Change oil (3) Winter: Leave gas in tank, use STABIL (4) "Don't ever use STABIL it will destroy your equipment!!"