Yamaha Four Stroke Leaking

[okeechobee]

I own a Yamaha 75hp, 2009 four stroke engine. It has always worked well. I live in Northern Indiana and at the end of last season (October). I had the motor winterized, has the lower unit gear oil changed and an oil changed. I have this same person store it inside but it is not a heated building. I got the boat back 3 weeks ago and it ran fine but I noticed that something (gas, oil or grease) was in the water. I watched it for a day and called the guy that winterized it and he eventually came over and saw the same thing that I did and thought it was residue oil from the oil change. It has been a slow leak everyday and yesterday I called and told him that there has to be something wrong. He came to get the boat and called me and said that the motor has a gas leak and that there is water in the oil. He said that it is as gas gasket leak. I can't believe these two issues are related (water in the lower unit oil and gas leaking). Anyone have any idea what I should be looking for in addressing this problem? Thanks.

[TownsendsFJR1300]

Your post is kind of confusing but I think it boils down to water in the lower unit oil.

There are several seals, seals wear out. Could be good today, starts seeping water into the lower end tomorrow. It sounds like a re-seal is in order.

They pressure test the LU without oil in it and it should hold a certain PSI for x # of seconds. I suspect yours will fail.. Once re-sealed, it should be good.

**I'm assuming the lower unit fill and drain plugs are tight (and NOT stripped) with new gaskets on them from the last oil change.

Re the gas leak, could be, however oil leakage from the LU will leave a sheen like fuel atop the water. Some more investigation is required there (if there is even a problem with fuel)

[TownsendsFJR1300]

Capt

Short de-rail, how'd you end up fixing the broken cowl latch?

[TownsendsFJR1300]

Nevermind, didn't look at the picture first...

Amazing the fiberglass stayed and the pot aluminum bracket was the weak point..

[okeechobee]

Thanks to all. After reading your posts I called the individual who winterizes and stores our pontoon. He explained that there was no gas leak but there is water getting into the lower unit oil. After inspecting the motor he feels the seal behind the prop has failed. He went onto say that there are three seals that are in the lower unit, one behind the prop, one going into the upper unit where the drive shaft enters the upper unit and one in the water pump and he is replacing all three. He indicated they all come in the kit and I might as well replace all three while it is apart. I do not know if this is true or not, but replacing them all seemed reasonable. Should I have the water pump impeller replaced as well? Thoughts?

[TownsendsFJR1300]

Not sure what model your engne is but should be the same.

Here's the parts fisch with all the seals displayed;

2006 and Later F75TLR Yamaha Outboard LOWER CASING DRIVE 1 Diagram and Parts

There's actually TWO SEALS adjacent to each other on the output shaft(behind the prop), plus a large O-ring, TWO SEALS on the verticle shaft from the engine, again, adjacent to each other. (#32, #63, #64, #36)

IMO, yes, replace every seal in the kit.

They also make a Water Pump kit. Unless your pump is less than a year old, I'd get the kit and install it. Your there anyway and all those parts have to come off anyway..

[okeechobee]

TownsendsFJR1300:

Good advice, I thought the same thing on the water pump kit. It is 5 years old and has never been replaced. Thanks