1955 evinrude fastwin 15 water in gear oil

[bryceman2712]

I recently bought a boat with a 1955 Evinrude fastwin 15 hp, first time taking it out and I ended up with water in the lower unit oil. Some guys on here helped me find the seal kit for this lower. now I'm taking it apart to do my pressure test and the drain screw had no gasket. I did a pressure test at 10 psi and nothing is leaking I've sprayed everything down.

Could a single drain screw really leak water in and gear oil out? This entire outboard was recently restored and looks and runs great so I don't want to screw up the lower unit. Should I put new drain and vent screw gaskets and run it or take it to professionals? Appreciate everyone's advice on here so much.

 

[lindy46]

Yes - just replace the drain screw and vent screw washers and run it again. No sense tearing into the gearcase if that's all it is.

 

[clemsonfor]

Yep put the screw seal/washer on and run it. It needs a seal for a reason. But if you just had a little bit of water there is no problem enjoying the motor with fresh oil over the weekend. Just check each evening to see how much water comes out. Sounds like it will just be a few drops . Gear oil can absorb water and still work. If there is water let it out then top it off.

But if it holds pressure chances are it will hold water out with new gasket/seal on plug

 

[Crosbyman]

10 psi is a good start do a vacum test also .

some folks don't bother doing the whole GC seal kit and just change the oil mid season and at bed time.

used proper seals for the vent and oil screws .. some nylon washers at the hardware store are to stiff.