Leaking oil from intake after every use

[ludwigsplat]

I have a 2 stroke Mercury 75hp (1997) with very low hours. Every time I bring it back from use, wash/flush it immediately afterward, the next morning I find an oil leak in the driveway. The oil is coming from the water intake, running down the skeg, then falling to the ground. Is this normal?

Ive owned the boat for a few weeks and this has been the trend. I know other people have talked about this, but this seems to be a larger amount of oil than others have mentioned.

 

[Texasmark]

Get several 16 oz cans of Sea Foam and run it with your regular gas/gas mix till it's all gone. Then re-ask the question. Directions on the can. Seems your combustion chambers and exhaust need a cleaning out. WW or auto parts stores has it, white can, red lettering.

 

[Faztbullet]

Check the lower unit oil for water contamination.....

 

[GA_Boater]

Pop off the cowling and see if oil is dripping. Do you have an oil tank on this motor and is the color of the oil the same as what you fill the tank with? Is fuel dripping from the carbs?

Also have you changed the lower unit lube? If yes, was there water in the lube? When water displaces lube, the lube is forced out and has to go somewhere.

I don't see how Seafoam will help with this one. I don't feel the dripping oil is coming from the inside of the motor.

 

[Chris1956]

Smell the oil. If it stinks, it is gear oil and you have a bad seal in the gearcase. If it smells like gas or regular oil, it is residual fuel. Check the carbs for leaks.

 

[ludwigsplat]

I drained some lower unit fluid. There was water, then cloudy oil. It was bad seals in the lower unit. Time for maintenance!

 

[Texasmark]

Well folks, I didn't go after the LU oil on this one because it was above the gearcase. However, since the smoking gun was found, it seems that the water ingestion must have pushed oil out either the shifter seal or the drive shaft seals.....probably the shifter seal. Can't win 'em all. Glad he found the problem.

 

[Chris1956]

The driveshaft seal in the base of the waterpump often leaks. The easy fix is to replace the watrpump base. Sand any rust or dirt off the driveshaft and lubricate the driveshaft, so the new seal won't tear.

 

[ludwigsplat]

No Title

Alright, so I took to a reputable mechanic and had them replace the seals in the lower unit, new 'racing performance' lower unit oil, and a handful of other annual maintenance things.

I got it back yesterday, took it out on the water for an hour, then parked it in the driveway. I got a little bit of oil coming out of the intake ports again. I moved the boat into its parked position and found this today:

The new oil leak is blue.

To clarify, the oil comes out of the intake ports then rolls down the skeg before falling to the ground.

 

[MH Hawker]

that is the merc HP lower unit oil

 

[MH Hawker]

that is the merc HP lower unit oil

 

[ludwigsplat]

So they probably didnt do the seal job properly? Too much oil and this is overflow? What do you think would be the cause?

 

[Texasmark]

Take it back to them and have them drain the oil and pressure test the LU gearbox while it's empty. You may have a crack in the LU casting that you can't see....possibly from winter freezing with water in the oil which does happen!

 

[ludwigsplat]

Final report: I took it back to them and they fully repaired it within two hours. You could tell they wanted to make it right because the four man team all came around to work on it. They apologized sincerely and said that when they put the new seals in and reassembled the lower unit that it just barely wasn't lined up right

....so to me that means the first mechanic was lazy and his boss had to fix his mistake...

No more leaking thankfully.