oil leak

[Basil]

I've got a '79 Johnson 70. After giving it a trial run after a year in storage, I noticed oil is leaking from a small (1/8")hole in the lower unit, just below the joint with the leg. <br />a) What is the hole for?<br />b) why is oil coming from it?<br />Any help would be appreciated.

 

[OBJ]

Re: oil leak

Hi Basil....welcome to iboats.<br /><br />The hole is a cavity drain. Its' purpose is just to let the water out of an area that has no way of draining other than the hole.<br /><br />The oily residue is probably just exhuast oil. Not all of the premix oil burns during combustion and ends up in the exhaust. Eventually, gravity lets the oil drain down. If it's blackish and smells burned, nothing to worry about.

 

[Basil]

Re: oil leak

Thanks for the info. Unfortunately, the oil coming out is new and clear, I suspect leaking from the shaft seal in the lower unit. Will pull it and see what I'll find. Hope the seal isn't a bear to replace.

 

[mike481050]

Re: oil leak

Sounds like a leaking gearbox seal. Have had this happen a number of times over the past 30 years with the same result each time. Leaking seal!