Yamaha F150 Oil leak..Need Help

[kiwimex]

Hi guys, I have used my boat twice over easter about a week ago, I pulled both batteries out last week and gave them both a full charge as the boat had been sitting for 4 months prior. When I put the batteries back in today, I just turned over the motor to make sure the batteries were good....I did this 3 times once on each battery and once with both.......The engine just started and I shut it straight down each time. I got off the boat and noticed a drip of oil at the base of the leg coming out between the prop and housing......As I had dry started the engine there was a little bit of very light smoke coming out of the prop/exhaust. Heres my question where is this oil likely to be coming from? could it be a seal from the water pump? the tell tail pumps well in the water and pumps less on muffs.


The engine is a 2013 F150 with 53 hrs on it

1) The boat sat for a week no oil leaking
2) I took the prop off and there was no oil leaking from the shaft seal it was black but dry, the outer area (exhaust) part showed oily signs.
3) I checked the gear oil from the vent plug first...I had a little very clean oil come out of there....I then popped the lower drain plug and had the same very clean oil with no signs of water.
4) I put the muffs on then ran water for about 3 mins then started the engine and ran it for about 10-15mins....shut it down and checked for any oil....NONE I also checked the stream while the engine was running and had no oil in the stream, other then the initial oil that was cleaned out from the start up.
The boat has now sat for about 1 hr and still no oil.

I plan on heading out tomorrow in the boat should I be concerned? Has anyone had this issue previously?


Would appreciate some advice / help

Cheers in advance

Steve

[Mad Fish]

Hi Steve
My F150 Yammi 2004 model had the first sign of an oil leak which turned up on one of the cav plates as a drip that everyone said was a seal up under the power head. Turned out when you lifted off the cover and looked closely at the block
there was a small snail trail of dried salt sunning down the block. Sorry to say the motor block was completely corroded out after 800 hrs and fresh water flush after each outing. As per Yamaha's instruction to not start the engine during flushing.
I think they were two different issues for me but the oil leak started me looking closer at the motor block.

[Fed]

There is or was a service bulletin about Yamahas pooling oil behind the pistons then the oil seeping past the rings when sitting vertically or in negative trim.
Maybe your's seeped into the combustion area then pumped out the exhaust with the cranking.

I'll look for the bulletin.

[Fed]

This explains it better.

[kiwimex]

This explains it better.

Fed I think you have hit the nail on the head, I always leave my engine trimmed down and I have noticed a couple of times on start up a lot of initial smoke, then it goes away quickly...this happened when I dry started it for but 1 sec x 3 then I noticed smoke puffing from the exhaust.

I will change the way I store the engine and see how we get on


thanks for the information.


Cheers

Steve

[PixieAU]

Good advice for all motors it seems

[Noelm]

Good advice for all motors it seems
No, not all motors have that particular "feature"

[PixieAU]

Oh, well good to know anyway

[Swanie1975]

My Suzi df140 did the puff of smoke thing the other day....I think I need to go boating more often as a preventative measure