Hello Happy Easter, Went out yesterday to help my buddy get his boat ready. He has a 1998 Johnson 50 JSTLECC. He told me when he went to winterize it he had a really hard time getting it started after sitting a month or so he took it to the mechanic the mechanic said the carbs were full of oil like the oil is seeping threw just sitting there. So we tried to start it yesterday and it took 20 minutes or so to get it started and running and we could see oil dripping out of the carbs never saw that before.He wants to unhook the VRO and mix his own fuel/oil, I told him hold off on that for now i would try to get some answers. Anybody have this problem before.
The reason I asked was becuase I left mine up and had a similar problem. From what I gathered from other discussion when the gas evaporates the oil is left behind and pools. If it is tilted up gravity does it's thing and the oil goes toward the intake instead of the cylindar. Sorry I couldn't help more.
04-03-2018 08:06 - edited 04-03-2018 09:14
Most often there is leakage in the oil outlet check valve due to wear or debris that affects the sealing of valve. With temperature changes and the fact that the fill cap vent is a one-way device to allow air in to displace consumed oil, pressure can build up in the oil tank. Normally the check valve stops any oil from getting into the fuel pump chamber until an oil pressure pulse opens the valve.
In some cases owners crack the oil cap slightly to allow full venting of the tank, but a fuel-oil (VRO - OMS) pump replacement is recommended as the check valve is not repairable. If the oil tank is mounted above the level of the pump, such as in a pontoon boat, sometimes a siphon action can do the same thing.
Another thing that causes oil buildup in the carbs is if someone runs the motor out of fuel for winterizing. On a VRO or OMS equipped engine, you should never let it run dry on gasoline as the oil pump keeps delivering lubricant as the motor is running out of fuel. For each revolution, the engine is receiving more and more oil and less and less gas.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.