Oil Leak Tohatsu 18HP

[Michael Bryson]

Oil Leak Tohatsu 18HP

I recently put my dingy on my trailer to do some maintenance. I tilled the motor down and left in in my garage. after a few days I noticed a small amount of oil on the garage floor. it seams to be coming from the weep hole next to the lower unit oil fill hole... engine oil level looks normal...any ideas what is causing this?

Thank you,
Michael

 

[Sea Rider]

Re: Oil Leak Tohatsu 18HP

If a 2 strokes, usually unburned gas/oil leftovers from combustion chamber specially if dark and gummy which drains by inertia, nothing to worry about..

Happy Boating

 

[pvanv]

Re: Oil Leak Tohatsu 18HP

Assuming your model is MFS18B2.

Could be nothing, or might be something. Does it have the aroma of LU lube, or of motor oil?

If LU lube, it may be due to a bad seal at the water pump.

If motor oil, could be some leftover drippage from filling the crankcase (that made its way through the lower cowl drain)... or it could be from a slight over-fill of the crankcase, or from having laid the motor on the wrong side for a few minutes.

If you are sure its motor oil, and everything else has been ruled out, you may have a leaky lower crankshaft seal, or a poorly-torqued crankcase casting.

 

[TOHATSU GURU]

Re: Oil Leak Tohatsu 18HP

If it's engine oil, it's okay.
If it's black, it's okay.
Amber or gray from the lower unit, you have a leak.

 

[Michael Bryson]

Re: Oil Leak Tohatsu 18HP

its a 4 stroke

 

[pvanv]

Re: Oil Leak Tohatsu 18HP

its a 4 stroke

Identify whether it is motor oil or gear lube. If gear lube, definitely a leak.

 

[Michael Bryson]

Re: Oil Leak Tohatsu 18HP

it looks like engine oil but how can I be sure? the motor was tilted in the up position most of its life but I have never laid it on its side....
now it stared leaking in the down (running ) position....

 

[TwoRivers]

Re: Oil Leak Tohatsu 18HP

it looks like engine oil but how can I be sure? the motor was tilted in the up position most of its life but I have never laid it on its side....
now it stared leaking in the down (running ) position....

Take a good whiff then walk away.
If it smells nasty and the smell is still in your nostrils ten minutes later, it's gear lube.

 

[Guest]

Re: Oil Leak Tohatsu 18HP

it looks like engine oil but how can I be sure? the motor was tilted in the up position most of its life but I have never laid it on its side....
now it stared leaking in the down (running ) position....

the Only way I can recommend is to change the Lower Unit oil, Run it in a garbage can for 10 min and check the color of your lower unit oil Or drain the oil and pressure test it.
http://forums.iboats.com/mercury-mariner-outboards/mercury-15-2006-4stroke-water-lu-638713.html