Problem with Gearcase 1975 135hp

[kci5477]

135ESL75<br /><br />Running engine out of the water with hose attached. Not above 2000 RPM's<br /><br />I noticed black colored thick oil coming from the prop exhaust. Thought it might be 2 stroke oil and seafoam that I was using to decarb.<br /><br />Put it in the water and ran a total of 2 miles. Took the boat out.<br /><br />A few days later I started the motor up with the hose attached and once again noticed a lot of black runnie oil coming from the prop exhaust. I then drained the gearcase oil and the oil was an olive green color and about 23oz drained out.<br /><br />When I filled the gearcase a few weeks ago I used Sierra Hi-Performace Synthetic Blend Gear Lubricant and I used about 28oz to fill the gearcase. This oil has an olive green color or cooking olive oil color to it from the start. What should it look like after its been running in the lower unit for a while? The oil that drained from the gearcase has the same color tone but it, lets say, was not clear like it was when I filled it. When drained it is no longer clear in color. <br /><br />I did a presure test with the lower unit still attached to the motor It held 16psi. It held that psi for 20mins before I removed the tire valve from the top hole, plus it held that psi after I turned the flywheel, prop, etc. It holds presure, therefore, I would say the seals inside are good and not leaking. Do you agree?<br /><br />Is the oil color correct for the type I used? I would say there is water in the oil but I have never used this oil before and it might be ok.<br /><br />I have provide a picture below.<br /><br />Hope someone can help.<br /><br />Thank you,<br />Kemper<br /><br />

 

[OBJ]

Re: Problem with Gearcase 1975 135hp

Do the pressure test and follow that up with a vacuum test Kemper. Remember to rotate the prop shaft, drive shaft and shift the gears to move the shift rod up and down with both tests.<br /><br />You didn't give to much history about the engine so, have you had the engine long or is it new to you? <br /><br />Black gooey oil from the prop usually is unburnted fuel mix oil that collects in the exhaust tube and migrates down once the engine is upright and sets for a while. This can suggest poor combustion from too much oil in the fuel, bad plugs, a cold running engine or maybe weak spark. <br /><br />But....lets check out the gear case first. Let us know what you find on the tests.

 

[kci5477]

Re: Problem with Gearcase 1975 135hp

OBJ - Please read my original post again. I was editing while you were replying. I have provided updates the presure test and a picture of the oil color and type I was using.<br /><br />This motor is new to me. It runs great. I just am concerned about the gearcase. I did replace the impeller when I got the motor a few weeks ago.<br /><br />I hope you can help.

 

[wilde1j]

Re: Problem with Gearcase 1975 135hp

The drained oil in the pan looks like it has water in it. Did any water drain first when you opened the drain plug? The pressure and vacuum tests should be done with no oil in the LU. Oil will make the results. Do NOT exceed 15 psig on the pressure test. Some pressure or vacuum should be there after 45 minutes.<br /><br />BTW, the water pump has nothing to do with the LU integrity.

 

[kci5477]

Re: Problem with Gearcase 1975 135hp

No water drained first. This is how it looked when it first came out and was finishied. The new oil going in was a cooking olive oil green color.<br /><br />The presure test was done with NO OIL in the LU and it has held the 16psi for 2.5 hours now.<br /><br />I did find other posts from "whosmatt" and they stated "synthetic lower unit oil is dark green in color." <br /> whosmatt post about green oil <br /><br />I think this synthetic oil is what has scared me.<br /><br />Do the experts agree?<br /> <br /><br />Kemper

 

[kci5477]

Re: Problem with Gearcase 1975 135hp

I am just going to use NON synthetic gear oil, take it for a short spin and then check the oil color. I will let everyone know what I find.

 

[Solittle]

Re: Problem with Gearcase 1975 135hp

If you are using a quality marine gear oil and your gearcase is not leaking water I would not be concerned about the color. Make sure you use new gaskets on the fill and drain plugs.