1992 Johnson v4 90HP Leaking Oil down Case ????

[MuskyHunterDave]

Hello. . . . .

I recently noticed a small amount of oil running down the outside of the case below the power head, and was wondering what this might be??

I pulled of the beauty plastic (below the power head), and one of the long exhaust bolts was loose, so I retighted them. . . .

It only happens after a long day of fishing, and it is not much oil.

I AM RUNNING MIXED GAS AND THE VRO IS Disconnected on the oil side, so that is not the sorce.

Could this be the exhaust gasket at the base of the motor, and if so how hard of a job is that to replace, or what kind of price should i expect at the repair shop.

What damage can this cause, if it is the exhaust gasket and the motor is used ??

Thanks in advance for the advice

 

[emdsapmgr]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

Is the oil black and looks like tar? It may well be the powerhead base gasket. Not an unusual failure for the V4's. Will probably get worse with age. Usually with this failure, you also get exhaust bleeding in the cowling-then it gets sucked back into the carbs. A messy, dirty problem. You will need a 3-4 hours of time and a new base gasket (about $10). The lower cowls will need to come down, and remove the bolts/nuts that hold the powerhead. The powerhead and shifter will need to be disconnected, but not dismantled. Lift it up about a foot and clean the old gasket. I would expect a reputable shop to also charge to fire the engine up and test it, once the work is completed.

 

[MuskyHunterDave]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

Yes the oil is black / tar looking. . . .

SO is it called the "base Gasket" or exhaust Gasket ??

I am quite mechanically inclined, but no outboard specialist, is this a relatively easy task, or should I have a shop do it ??

Thanks again for the advice

 

[MuskyHunterDave]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

Will it hurt to run it like this, as I have a couple fishing trips planned soon, and not sure I will have time to do or take it to the shop for repairs, but if it is going to damage anything I will cancel the fishing trips

 

[Thumpbass]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

I don't know how the '92 models compare but my '79 100hp had a similar symptom and it was because the gasket between the air silencer cover and base was allowing fuel to drip into the lower cowl and eventually run down the housing...my buddy has a '79 150 and his does the same thing. My understanding is that stuff should be draining back into the maifold but in these cases some is escaping and running down the motor.

 

[emdsapmgr]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

Usually the base gasket fails and permits exhaust to exit into the cowling. While dirty and smokey, it is probably not going to create a failure. The base gasket also passes water from the lower unit to the powerhead. Be sure that exhaust is the only thing leaking (not water.) If it is running normal temps, you should be OK till you fix it.

 

[ngreene22]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

i have a 1998 115HP V4 Johnson that I noticed is doing the same thing. It is getting worse as it sits in the winter. I can not tell where the oil is coming from. Somewhere under the motor cover. It is running down the back of the case below the powerhead. Could it be the powerehead gasket? The motor runs fine.

 

[bradfordh]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

If its blue or green oil then its a leak somewhere on the fuel system probably a carb. It drips down into the lower plastic cover and the down onto the lower unit the gas evaporates and all thats left is oil. Pretty common but not cool.

 

[wrosales]

Re: 1992 Johnson v4 90HP Leaking Oil down Case ????

I have the same motor (Evinrude 1992 E90TLEND) and this was the very first thing that I had to do to mine. I had never done any repairs on any kind of boat motor and I managed to get through it with only a few problems. The main thing that slowed me down was the fact that my motor had been in salt water so the bolts were a major problem. A few helicoils later and I had it up and running. You should have no problem. Very easy. Good luck.

William