1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 57Get this manual
Off-Season Storage 1Use OMC 2+4 Fuel Conditioner in your fuel mixture to stabilize the gasolineIt eliminates need for draining fuel for up to one year of storageAdd one ounce of OMC 2+4 for every gallon of gasolineThen operate motor in fresh water for few minutes to allow fuel mixed with OMC 2+4 to enter carburetorInstall OMC Flushing Adapter Kit to operate out of water on trailer or dolly to prevent overheating damage to engineWhen an OMC Flushing Adapter Kit is used, remove the propeller before starting engine to prevent accidental contact with moving propellerAlways turn water on before starting engineControl water pressure as full water pressure may cause damage to engine