1988 Johnson 90 hp Tuneup Question

[turnstone]

I have just taken my father's 1988 90 hp Johnson outboard out of the winter storage. I noticed that there is a bit of oil sludge on the lower part of the skeg and coming out from around the prop area.

Am I leaking oil, or is this natural emission fronm last season's final exhaust outflow.

Also, how can you check the oil on a motor like this when it's on the water. Can you check oil level etc. like a car somehow? Or, do you simply change the oil every year and hope you don't burn it during a season of use?!

Thanks to anyone who can help!

[saxatilis]

I don't believe that you can check the oil as you would your car. In fact, the motor that you described is a 2 stroke engine that requires that oil be added directly to the fuel or to a VRO (small plastic oil tank). You can check the oil in the tank by looking at the tank from the outside (because you can usually see through the VRO tanks as they are milky white).

I believe that the oil you noticed may be from the lower unit, which requires lube oil which can not be added or checked when you are on the water. The best thing to do will be to put the boat on a trailer, lower to motor, and check the seals (where the lower unit attaches to the motor)for signs of leakage. If nothing is noticeable you may want to put earmuffs on the motor and run in for a while (with the motor in neutral only) and check the area where the prop attaches for oil leakage. Lastly, if still nothing is noted change the oil in the lower unit. When you do this make sure you replace it with an appropriate lube oil. Also, make sure to inspect the oil comming out. In particular, it should not be foamy that is a sign that water is getting into the lower unit. If you are not sure save some and show it to a OMC mechanic.

hope this helps.

[soukupj]

I just bought a boat with an 85 Evenrude and had a similar oily discharge from the prop. I talked with an OMC mechanic and he assured me this is normal for first starting up in the spring. The outboard engine release its exhaust out through the prop. Often in the spring, especially if your father winterized the cylinders by spraying them with light oil last fall, an oily discharge will come out the first few times you run the engine. This is a result of the winterizing oil washing out some of the carbon buildup in the cylinders. Nothing to worry about as long as its black. If it is more translucent and looks like fresh oil, it could be that your lower unit is leaking gear oil. If its milky, then you may have water leaking in to your lower unit.

As far as checking the oil,....your outboard is a 2-cycle engine. You have to mix oil with the gas. Some engines have a separate oil reservoir (under the engine cover) that you just keep filling up with oil (make sure you use the proper marine 2-cycle engine oil. Older engines do not have this feature and you have to mix the oil with the gas yourself. You should check the manual to be sure you are doing it the correct way for your engine.

It sounds like you may be new to the outboard engine scene. I recommend you go to a marine store and buy an OMC maintanence manual for your engine. they are very helpful and contain detailed instructions on tuneups and troubleshooting.

One more note....NEVER run your engine out of the water unless you first hook it up to a water source (hose) using a special adapter. You will cause serious permanent damage even running it for only a minute or so. Your outboard uses water to keep cool and if its not run in the water, it will overheat. You should see a thin stream of water shooting out the back of the engine while its running. This is a good way to check and make sure your water pump is working properly....if you don't see that water stream, shut it down right away to avoid damage.

hope this all helps....