Found Red oil in 1989 120 VRO Air Box

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
My 1989 Evinrude120 VRO looper has been running rough at idle. I live on a small lake and usually have the motor idling while we putt around the lake drinking beverages. I have never decarboned the motor so i bought some Seafoam Deep Creep and went to it. I warmed the motor up and pulled the Air Box off the carbs. The Air Box had a layer of oil in the bottom of the air box. I would say about 4-5oz of red oil. I have only used Evinrude XD-30 oil which is red. Judging by the gasket at the bottom of the air box this is normal but I was not sure. Is this normal? I have disconnected the VRO and pre mix all my gas and use mid grade gas treated with stabil marine. I am going to start using seafoam in every other tank to keep carbon at a minimum. The motor has very low hours but it is an older motor. The carbs have never been touched. I have never adjusted anything on the motor for fuel to air mixture. Right now the motor is marinating in Deep Creep. I plan to run it all out tomorrow and put new plugs in (still has the originals). Im hoping that will help with the idle issues. Any advice on either the idling issue or oil in the air box will be greatly appreciated.

Also the boat now sits at a dock in the water all summer, if that helps diagnose the oil issue.
 

jakedaawg

Rear Admiral
Joined
Jun 26, 2012
Messages
4,275
If you still have the original plugs in a 89 motor ther are a ton of preventitive maintenance items that also need to be done. The oil in the airbox is the least of your worries. Get a manual. Do all of the reccomended maintenance. That is where you should start. Your engine is designed to run on gas and oil. No amount of mechanic in a can will keep you from needing to do proper maintenance.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,151
check your airbox there should be a hose that goes from the bottom of it to the crank case make sure its not plugged. the hose is there to prevent that from happening and if its off or damaged its a vacuum leak. Get engine decarb from either evinrude or mercury both are good the seafoam is good just not as good. I use the omc 2+4 engine treatment. also change the waterpump
 

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
I have kept up on the maintanence. Lower unit oil change 2 times a year. New thermostats, new water pump 3 years ago. Replaced the spark wires all new fuel lines from vro to tanks. The plugs have always been clean and in good shape. I bought new plugs when I did the wires and it ran terribly with the new plugs so the old ones got cleaned regaped and back in. I'll check the hose to the crank. It must be plugged. Thanks for the advice. Seafood was originally sold by evinrude for decarbon treatment. I will look into the 2+4 for further treatments.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,074
I think you have gotten about all you can out of Seafoam and the other decarbon products you have used. It is time to find out where the oil came from. Start the motor and observe the carbs to see if any fuel leaks. See if the airbox hoses spit oil, and if so, track down the source. Some oil is normal.

Fresh fuel is the key to keeping the carbs clean, and I think you have that covered. However, floats and inlet needles do wear out, and can leak.
 
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