2016 F90 4 stroke leaking oil

[DennisG01]

Where ever the leak actually is could be a narrow drip line. That's why you need your detective hat and look at things REAL closely. Once the entire thing is cleaned up, it will make it easier to spot. Paper towels in key areas can help spot drips. With the amount that it's leaking, it shouldn't be too hard to find.

[zenoahphobic]

Where ever the leak actually is could be a narrow drip line. That's why you need your detective hat and look at things REAL closely. Once the entire thing is cleaned up, it will make it easier to spot. Paper towels in key areas can help spot drips. With the amount that it's leaking, it shouldn't be too hard to find.

And on that note, checking the oil level would indicate how serious a leak that this might be. I.e. it could have come from an oil filter change spillage that has no consequence to the oil level in the engine.

[99yam40]

And on that note, checking the oil level would indicate how serious a leak that this might be. I.e. it could have come from an oil filter change spillage that has no consequence to the oil level in the engine.

or if the motor is making oil and is over filled

[Keithbaja]

Tony, I'm loosing it. Lol. Oil pressure switch. Not a valve. My grandpa always said. "Just think,, it only gets worse" Its hard to tell from from your last pic
but I'm thinking that's the steering yoke. Yes/no ? M.M.

[TONYG279]

Tony, I'm loosing it. Lol. Oil pressure switch. Not a valve. My grandpa always said. "Just think,, it only gets worse" Its hard to tell from from your last pic
but I'm thinking that's the steering yoke. Yes/no ? M.M.

Yes, its the steering yoke, looks like a metal fork. The leak is just below it.

[Keithbaja]

Hi Tony, I'm playing hooked today. 7 days a week is killing me.. Dennis said it best. Clean, clean clean. Then inspect with a bright flashlight, (Coast) then tilt. Then drive up and down hills. No leak. Then run motor upper fast idle. Oil leaks are easy to locate. You must be methodical about it. If only leaks after running says volumes.

[TONYG279]

Hi Tony, I'm playing hooked today. 7 days a week is killing me.. Dennis said it best. Clean, clean clean. Then inspect with a bright flashlight, (Coast) then tilt. Then drive up and down hills. No leak. Then run motor upper fast idle. Oil leaks are easy to locate. You must be methodical about it. If only leaks after running says volumes.

Well up until now it shows the leak with the engine on only, i have not tested the boat in the water, just at home with a big plastic container.

[TONYG279]

when you say inspect with a flash light you mean take off the cowling and look everywhere? what if the leak is coming from a seal in the oil pump? or the crankshaft seal? will i see oil under the cowling if that is the case?

[Keithbaja]

Yes, but as someone has stated. Clean that motor good first. Tp or paper towel shows up leaks fast. Get a can of break clean and put the red nozzle on and spay that area super clean and let dry. Have GOOD smaller size flashlight and a small mirror on a swivel stick. Have wife,son, friend start motor and inspect that area u took pictures of. And as noted on this post oil (anything) can run down from somewhere else and end up pooling far from the actual leaking source. Its actually rather easy.. Or can buy a kit that adds a ultraviolet chem to oil and use a black light to find the source. I doubt u need that. Have u checked oil level ??

[TONYG279]

Yes, but as someone has stated. Clean that motor good first. Tp or paper towel shows up leaks fast. Get a can of break clean and put the red nozzle on and spay that area super clean and let dry. Have GOOD smaller size flashlight and a small mirror on a swivel stick. Have wife,son, friend start motor and inspect that area u took pictures of. And as noted on this post oil (anything) can run down from somewhere else and end up pooling far from the actual leaking source. Its actually rather easy.. Or can buy a kit that adds a ultraviolet chem to oil and use a black light to find the source. I doubt u need that. Have u checked oil level ??

Yeah i believe it was a little low

[TONYG279]

Update: we removed the lower unit and the power head. First issue we found was yamaha is using garbage components in their engines, i will upload a picture so you can see how corroded the lower unit shaft looks. The leak doesn not seem to be coming from the crankshaft seal or the pump itself, they look clean. We will replace the pump seals anyway

[TONYG279]

That corroded hole is where the oil seems to be coming from.

[fairdeal]

its a steel plug, so apparently rusted through...

A bizarre degree of corrosion - as evidenced by the driveshaft also.

[Keithbaja]

Yep, yammys suck !! I dont want to hear all you fools saying " I spent so much on this outboard " It has to be good.. The only reason I as a master tech and captain come to this website is confirm what junk is being sold. Get a grip.....

[Keithbaja]

Thanks for the update. Yamaha makes a lot of good products, outboards are not one their better ones