My 2001 90HP yamaha is leaking oil (big time) out of the top of the tank oil level sensor cap (at all times)though it seems tight; plus, the low oil level buzzer goes off even when it is full. Could the cap merely not be sealing -- if so, why would the buzzer sound?? 
The motor seems to run fine with a fine sent of oil in the fumes.
The motor seems to run fine with a fine sent of oil in the fumes.