Yamaha Outboard Oil Tank Sensor Leak

I decided to also replace the drain line that comes from the bottom of the oil tank and re enters at the top of the tank.

Yamaha outboard oil tank sensor leak.

I don t know whether it is engine oil lower unit oil or something else. I am the second owner of this matching 2007 19ft. Oil sending unit leak i just found this same leak from the oil sending unit on my 06 90hp after taking the boat out of winter storage. Eventually the main oil tank overfills and spews excess oil out a vent tube into the air silencer box.

I cleaned up the rough edges on the oil reservoir neck top and perhaps this may reduce the oil leaking from the low oil sensor cap. Piston picture at end. I have a 2004 90 hp yamaha ob. The yamaha outboard alarm system can fail just like any other system on your outboard.

Its leaking oil at the reservoir tank ware i think its the low warning oil sensor. Oil leak on yamaha 4 stroke outboard discussion in boats and motors started by bmagill jan 23 2010. Can answered by a verified marine mechanic. So my thought is forget tie wraps and replacement of oil sending units i want to fix this thing permanent with an external oil tank like on the bigger outboards.

I put thread tape around the two small raised ridges about 3 wraps that are down the tube a little and around the tank lip where the cap snaps over. G3 and 90 tlrc. Jan 23 2010 1. Yamaha could do a better job of engineering this bit.

Given the head of oil above the part of the tank the sensor sits on it is no wonder this can leak. While the outboard is tilted a leaking rubber cap on the main tank can result from improper assembly or from twisting out of place.