'99 Yamaha F100 Oil Leaking Around Prop

[Timbit]

Hello, My dad changed the gearcase oil last week and today we went out to get the boat ready for fishing tomorrow he seen alot of oil leaking out from around the prop. What would cause this seal to break, and isthis a do it yourself kinda job or should we take it to the dealer to get fixed.<br />also if anyone has any schematic for the lower end please send me a link to see it

 

[rodbolt]

Re: '99 Yamaha F100 Oil Leaking Around Prop

depends on what kind of oil it is and if its leaking from the propshaft,driveshaft or shift shaaft seals. could be the filling method used. could be its just its time.

 

[Timbit]

Re: '99 Yamaha F100 Oil Leaking Around Prop

It turned out that is was the seals that were gone, my dad took it to the marina to get fixed and he found out the hard way that it is REALLY important to change the gear oil BEFORE the winter. The oil had water in it and froze over the winter and the gearcase cracked as well as blowing out the seals. Very expensive to have fixed.

 

[rodbolt]

Re: '99 Yamaha F100 Oil Leaking Around Prop

ouch<br /> yep its not cheap. which is why I always reccomend before allowing any engine to sit more than 30 days to check the lower oil and engine oil for water. most all outboards are self draining and cold wont affect them, however all are susceptible to water intrusion damage. so usually when we "winterize" an outboard all we are doing is preserving the internal shiny parts and preventing the fuel system from deteriorating. I have some striperfisherman and some duch hunt clubs that I "summerize" the boats. they are used from about nov to about march. only took a few gearcases and powerheads and they learned why preservation is nessasary.