1990 johnson gt175 leaking oil

[mavmike72]

Buddy of mine has a 175 johnson and we were in the garage looking at the back of the motor and noticed oil leaking. The motor was trimmed all the way down. The oil was black and coming from under the motor cover at the top running down the lower unit. Thanks so much for your help.

 

[Islandbrah]

Re: 1990 johnson gt175 leaking oil

Older outboards tend to drip a little trail of that oily discharge just below the base of the cowling by the upper exhaust ports. check compression just to be safe. if it was excessive then you definitely have an issue. It could be an early sign of a rebuild in the future. Excessive discharge could mean not all the fuel oil mix is burning in the cylinders, too rich maybe, bad spark to a cyl. need to dig deeper before you'll get your answer.

 

[mavmike72]

Re: 1990 johnson gt175 leaking oil

Older outboards tend to drip a little trail of that oily discharge just below the base of the cowling by the upper exhaust ports. check compression just to be safe. if it was excessive then you definitely have an issue. It could be an early sign of a rebuild in the future. Excessive discharge could mean not all the fuel oil mix is burning in the cylinders, too rich maybe, bad spark to a cyl. need to dig deeper before you'll get your answer.

What doesn't make sence it hasn't ran in 6 weeks. It also ran great the last time.

 

[mavmike72]

Re: 1990 johnson gt175 leaking oil

Any ideas what to check?

 

[mavmike72]

Re: 1990 johnson gt175 leaking oil

ttt

 

[emdsapmgr]

Re: 1990 johnson gt175 leaking oil

Your engine is the bubble back model. On that engine, there is a rectangular oring (323625)that is sandwiched in a machined groove between the engine and the midsection adapter. These orings can fail with age and can leak black, oily unburned exhaust smoke and tarry residue into the cowling area. You can pull the powerhead and install a new oring. About a 3 hour job. You will also want to replace the powerhead base gasket 323214. It's not an imminent failure issue, but left as is, you will find that the leaking exhaust smoke will migrate under the cowling area and will get sucked back into the airbox and into a running engine-that's the problem.

 

[mavmike72]

Re: 1990 johnson gt175 leaking oil

Is this a job that some one machaniclly inclined can do? My buddy called a boat shop and they said if you don't no what your doing don't do it. I told him they just want his money thats why they said this. They wanted 350.00 to do it.

 

[emdsapmgr]

Re: 1990 johnson gt175 leaking oil

The dollar amount quoted is about right for the flat rate for the job-if done at a dealer. You can do the job yourself for the cost of the gaskets. If you are mechanically inclined, get a factory service manual, along with some type of hoist. You will have to get a puller to lift the powerhead up (by the flywheel) enough to scrape the old composite gasket off and install the new one and the oring. You don't have to take anything on the powerhead apart. You will need to remove the two adapter covers (under the lower cowling,) cable/linkages, telltale hose, unplug the wiring harness red plug, disconnect the shift rod and probably the feed fuel line. Don't take the exhaust bubble off the powerhead-it's a special factory fit. You may scrape a few of your knuckles before you are done. An original factory manual is avalable from Ken Cook Co., out of Milwaukee. They are also on the web.

 

[psteurer]

Re: 1990 johnson gt175 leaking oil

It could be an o-ring problem. But a small amount of fuel could also cause this. One time I had a small leak from my primer solenoid. The fuel mixed with all the crude in the bottom of the engine housing and slowly leaked down the mid section. When you tilt your motor you can also get a small amount fuel come out of the carburetor. You could also have a disconnected recirculation hose. I would recommend you check inside the motor next time you give it a run to see if there is any sign of what is dripping down.

 

[mavmike72]

Re: 1990 johnson gt175 leaking oil

Thanks guys will check it out.