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. Can answered by a verified marine mechanic. 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.

Eventually the main oil tank overfills and spews excess oil out a vent tube into the air silencer box. Troubleshooting the alarm system includes making sure the horn associated with the alarm works making sure the warning light comes on and the horn sounds when the oil level drops below acceptable levels and ensuring the warning sounds if the engine overheats. Piston picture at end. 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.

Jan 23 2010 1. A plastic tie wrap snugged around the rubber lip usually cures the leak. 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 have a 2004 90 hp yamaha ob.

Noticed the last few times out that i have an oil leak coming from this area of the outboard see pic. The yamaha outboard alarm system can fail just like any other system on your outboard. 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.

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. I am the second owner of this matching 2007 19ft.