2017 Tohatsu 20 hp 4 stroke oil leak

[Webomatic]

Hello all - I've got a 2017 Tohatsu MFS 20C Electric start / trim motor that leaks oil after use. It starts and runs like a top but when I get it home, after a few hours there's a pool of oil on the floor under it. It seems to be dripping down from the crankcase area? Is a bad gasket common on these motors and is it a difficult repair? I live in Roseville, CA and I can't find a mechanic that works on Tohatsu within a hundred miles of me. Any insight or information would be greatly appreciated!

Mark Weber

 

[pvanv]

OK, 20C. What is the oil level on the dipstick? Even a hair above full is an issue. No, gaskets are good on these. Any Mercury mechanic has the same motor as a Merc and can work on it... just not under warranty.

 

[Webomatic]

Thanks for your response Paul. I bought it used on a 14' Gregor skiff. The Trailer sits low so I was towing it with the motor tilted full up. I did notice that when I first got it that the oil was a bit too full. I saw a sheen around it every time I put it in the water but I thought that was gas because I had a bad fuel pump and leaky fuel line. When I store it in my garage it's tilted full down and after a few hours there's a pool of clean oil on the garage floor, no matter what the dipstick level? It's not the drain plug that leaks. It's coming from what appears to be the crankcase. I talked with a couple of Merc mechanics and they didn't want to bother with it fir some reason? I usually go through a quart of oil every 5 uses or so. None is leaking into the engine and it starts and runs great. I'm stumped.

 

[pvanv]

That is a huge use of oil. Typically, 4 strokes make oil, not use it. If the oil is that clean, maybe it's LU fluid; motor oil usually gets pretty brown pretty fast. There is an oil seal at the bottom of the crankshaft, but I have never seen one leaking.

 

[MattFL]

Clean it up squeaky clean with degreaser, take any plastic cowling off and let it sit until it leaks. See if you can figure out where it's coming from.