89 johnson 40hp outboard motor leaking oil, lower unit

[slteel]

About 6 months after I pulled the boat out of the water for the season, I noticed oil had dripped down the prop and made a small pool on the ground. It looks like the oil originated at the seam of the lower unit. Do you think this is a gasket problem? Should I add some oil? Can it be put in the water and test the motor or will that damage the it ?
Thank you for your advice.

 

[tashasdaddy]

Re: 89 johnson 40hp outboard motor leaking oil, lower unit

check you lower unit oil to be safe. and always change the washers when you remove the plugs. most likely it is left over unburnt, gas/oil exhaust, that has run down the inside of the exhaust housing. fairly common.. suggest doing a decarb on the engine.

 

[Lodgepole]

Re: 89 johnson 40hp outboard motor leaking oil, lower unit

If oil is coming out, then water can get in. If this is gear lube and not stinky black unburned motor oil, then I would open the gear case and get everything in good shape. Gasket, prop shaft seal, drive shaft seal and shift rod seal. Also I would replace impeller if it has not been recently replaced. You might get by temporarily by filling gear oil level. First open lower drain plug an see if any water comes out or oil is is milky, this is a sure sign you need to re-seal.

 

[iwombat]

Re: 89 johnson 40hp outboard motor leaking oil, lower unit

90% of these posts are just unburned two stroke oil making it's way out. I'm guessing that's what we have here. Check the LU lube to be sure.

 

[GEY203X]

The Lube that comes out of My Johnson RDSL23 40 H.P. is the Mercruiser Jade Green Quick Silver Gear Lube Because We end up Throwing all kinds of Different 2 Cycle oil of Different Colors in the Tank and it's always the Green Gear Lube that Weeps off a little Bit. If You probe up in the Vent Hole You can Actually Coax a little more out.Except for the time Both Vent/Drain Screws complete Disappeared, No External Water gets in there so it's not Milky Do to External Seal leaks including Prop Shaft output seal or Either Drain/ Vent Screw Seals.I know this Gets Overlooked a lot, anytime you're in the gear housing to do any work like the water pump impeller and cup any seals. You should always apply the pressure and vacuum tests to the gear housing and make sure it can hold both vacuum and external pressure. If it doesn't then you know you've got seals in there that have to or you know i water will come the other way

 

[saltchuckmatt]

Your responding to a thread in 2007....not sure their going to hear it.