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Yamaha F115 Main Crankshaft Seal blown twice - advice?

S

stwax

New member
I have a 2014 Yamaha F115 on a 2014 Avalon Pontoon (24'). Used in a salt water river in Virginia. Engine is well taken care of. Rinsed out after every use. Had impeller and oil changed this past winter. Etc.

I was running boat WOT in July. Alarms went off. Oil behind engine in water. After restart, as long as I stayed below 2K RPMs, alarms would stay off long enough for us to get home. According to mechanic, main crankshaft oil seal below flywheel blew and lost pressure and oil. They repaired it. On my second trip out after repair (water was like glass; smooth ride), I was at WOT for about 8 minutes and the same thing happened. Alarm went off and could see oil slick behind boat. Took it back to shop and they confirmed, the seal they just put in blew. They are a reputable shop. Not trying to overstep or jump to conclusion that it was an improper repair after the first time but, I wonder if there is any advice I can find on here to direct them to what the problem may be.

Is this common for the F115? Is there an underlying problem with pressure causing the oil seal to fail? Any insights are appreciated. Thanks.
 
Not common.

Could be excessive crank case pressure. Could be just bad luck.

On some Yams they use a retainer to keep the upper oil seal in place.
 
Thanks for the quick reply boscoe. Any thoughts on what might cause excessive crank case pressure? As an aside, when running WOT, it runs at just near 6000 RPMs. Always has since new. I assume that is a normal RPM range and acceptable to be at that level.

Is the retainer you mentioned included with the original manufacture of engine or is it an aftermarket piece that can be added?
 
Happened to me today on humboldt bay. Ran wfo a few miles, pulled up to a stop, and it looked like the Exxon Valdez. Got a tow to the dock, and when i got home ,the crank seal had popped up out of its seat. You-tube vid looks like an easy fix , but what would make the seal blow out like that. What kind of crankcase ventilation is on a 2016 F115? Could that be the problem? Only 240 hours on it.
 
Bigbert121164 said:
Happened to me today on humboldt bay. Ran wfo a few miles, pulled up to a stop, and it looked like the Exxon Valdez. Got a tow to the dock, and when i got home ,the crank seal had popped up out of its seat. You-tube vid looks like an easy fix , but what would make the seal blow out like that. What kind of crankcase ventilation is on a 2016 F115? Could that be the problem? Only 240 hours on it.
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I agree. I am in MT and the local boat facility has not seen this before. I can tell u the old seal will not work as we tried that. At WOT it blew again. Pls let’s stay in touch as to the real long term fix. Thxs. John
 
Are you planning to take this in or repair yourself? I would like to know the cause??? The fix seems a bit hookie to me and not long term. I may write Yamaha a letter for action. Thought here
 
Something within the motor might be causing excessive oil pressure or crank case pressure.

A retainer plate could be crafted to physically keep the main oil seal from migrating outward. But this would be a bandaid approach if there is an oil pressure or crank case pressure problem.


retain.png
 
stwax said:
I have a 2014 Yamaha F115 on a 2014 Avalon Pontoon (24'). Used in a salt water river in Virginia. Engine is well taken care of. Rinsed out after every use. Had impeller and oil changed this past winter. Etc.

I was running boat WOT in July. Alarms went off. Oil behind engine in water. After restart, as long as I stayed below 2K RPMs, alarms would stay off long enough for us to get home. According to mechanic, main crankshaft oil seal below flywheel blew and lost pressure and oil. They repaired it. On my second trip out after repair (water was like glass; smooth ride), I was at WOT for about 8 minutes and the same thing happened. Alarm went off and could see oil slick behind boat. Took it back to shop and they confirmed, the seal they just put in blew. They are a reputable shop. Not trying to overstep or jump to conclusion that it was an improper repair after the first time but, I wonder if there is any advice I can find on here to direct them to what the problem may be.

Is this common for the F115? Is there an underlying problem with pressure causing the oil seal to fail? Any insights are appreciated. Thanks.
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Keep operating the motor with a known problem and a loose oil seal might be the least of your problems.
 
this happened to me on my 2016 115. first run of the season and all well till the alarms going off at 6200 rpm. the cause may have been the shop that winterized it did not remove old oil before putting new oil in. i did not check oil in spring before going out. had it replaced then went out for test and happened again. have not replaced it yet the second time. trying to find out cause.
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This happened to me on a holiday weekend on our pontoon equipped with the Yamaha VMax Super High Output VF115LA. Only 77 hours on the engine, and it does have the Rev-limiter. Pulling 2 small kids on a tube when the alarm went off. Shut off engine immediately and discovered a GIANT oil sheen behind our boat! Pulled the kids in through it. Ruined our $400 tube and the tow rope. Tried cleaning with detergent, but the odor is there forever, especially when the sun heats it up, so we had to toss everything. Oil sheen made its way into the docks near where we pulled the boat out. Neighbors were not pleased but were understanding. We were mortified having to take ownership of this unfortunate and embarrassing experience! Went online and found that this has occurred to a number of boaters, so asked the local Yamaha-certified service center manager if there were any Mechanic's Bulletins or Recalls on this issue. He ran the engine's ID/Ser numbers and said that Yamaha has not issued anything on this (main crankshaft upper oil seal popping out at WOT). Spent most of the rest of the weekend putting the original seal back in, since everything was closed for the holiday and no chance of finding a replacement seal. Have run the engine several times since, but never pushing it past 5000 rpm. Not going to pay to have a new seal installed, since others have already done so and had it pop out again after spending $$ and time lost with the service departments. Pretty much a deal-breaker and total bummer for us, since that is the rpm range required to get the kids and tube outside of the wake.
 
YAMAHA VMax SHO 115hp said:
This happened to me on a holiday weekend on our pontoon equipped with the Yamaha VMax Super High Output VF115LA. Only 77 hours on the engine, and it does have the Rev-limiter. Pulling 2 small kids on a tube when the alarm went off. Shut off engine immediately and discovered a GIANT oil sheen behind our boat! Pulled the kids in through it. Ruined our $400 tube and the tow rope. Tried cleaning with detergent, but the odor is there forever, especially when the sun heats it up, so we had to toss everything. Oil sheen made its way into the docks near where we pulled the boat out. Neighbors were not pleased but were understanding. We were mortified having to take ownership of this unfortunate and embarrassing experience! Went online and found that this has occurred to a number of boaters, so asked the local Yamaha-certified service center manager if there were any Mechanic's Bulletins or Recalls on this issue. He ran the engine's ID/Ser numbers and said that Yamaha has not issued anything on this (main crankshaft upper oil seal popping out at WOT). Spent most of the rest of the weekend putting the original seal back in, since everything was closed for the holiday and no chance of finding a replacement seal. Have run the engine several times since, but never pushing it past 5000 rpm. Not going to pay to have a new seal installed, since others have already done so and had it pop out again after spending $$ and time lost with the service departments. Pretty much a deal-breaker and total bummer for us, since that is the rpm range required to get the kids and tube outside of the wake.
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Recalls are for safety related items. Technical bulletins are issued for certain defects that rise to a certain level.

While you and others may have had an oil seal failure, as painful as they may be, in the scheme of things it does not rise to the level of a technical bulletin needing to be issued.

Once a seal has come loose (assumption being it is the upper crank shaft seal) they may be more prone to failing again. If you don't replace the seal you might want to think about fabricating your own seal retainer of some sort.

On a related note, hope that the motor is able to turn at or near 6000 RPM when pulling a tuber. Recognizing that when you are not pulling a tuber you must take care to not let the motor over speed.

Good luck.
 
You cannot just push new seal in. The block must be split to install new seal. Any other way will just come right out unless mechanically pin in in
 
Same happened to me. 2016 115hp. The seal just got pushed out, Yamaha took the cost for a new seal and a new timing belt, but not the repair cost.
The engine only has 160 hours of running, aprox 20% in full revs.
The workshop glued in the new seal and told me to be a little observant the next couple of days...... So i think they know this is a big problem.
I tried to get in contact with Yamaha directly, but that's a big nono...
Stay away from Yamaha and choose another brand. That's my best solution for this problem.
 
Merritt Island Fl. Not another one.. yes me too, 2016 Yamaha 115, same exact thing happened to me. Bought it brand new, it has 120 hrs on its and like new. I have been 100% satisfied with my Yamaha for 9 years....UNTIL NOW.......Do not purchase 2014-2017, and maybe others also, and, maybe yours........
 
Bek said:
Same happened to me. 2016 115hp. The seal just got pushed out, Yamaha took the cost for a new seal and a new timing belt, but not the repair cost.
The engine only has 160 hours of running, aprox 20% in full revs.
The workshop glued in the new seal and told me to be a little observant the next couple of days...... So i think they know this is a big problem.
I tried to get in contact with Yamaha directly, but that's a big nono...
Stay away from Yamaha and choose another brand. That's my best solution for this problem.
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2016 motor? I don't know of any motor maker that would cover a repair that far out of warranty.

What Yamaha? Yamaha USA is but a phone call away.
 
The snippet below showed up in my email this morning. No where to be found here now. ???

PCV stands for Pressure Control Valve. As in water pressure in the cooling system. Nothing to do with a Positive Crankcase Ventilation valve.

An F115 is not the same as a VF115. Only thing in common is made by Yamaha.

You gotta love the innerweb for factual information.

 
So the challenge is, how is crankcase ventilation/pressure managed in this engine? Because if it gets to high the seals blow...
 
The crankcase pressure is not managed. It is simply open to the intake manifold.

The intake manifold can take as much pressure as the crankcase can give it. With the thought that if blow by gets excessive the motor is going to be running like crap long before a seal should pop loose.
 
boscoe said:
Something within the motor might be causing excessive oil pressure or crank case pressure.

A retainer plate could be crafted to physically keep the main oil seal from migrating outward. But this would be a bandaid approach if there is an oil pressure or crank case pressure problem.


View attachment 30755
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Did you make this part or did you buy from somebody? Can you send link
 
Add me to the equation. 2017 Yamaha 115 with same issue…. Blowing seal and oil once 5k rpm are hit. Reset the seal and it did it again at less rpm. No service bulletin and mechanic had never heard of it happening. Has Yamaha come up with a resolution or is a class action suit on the offing?
 
Oldchevytruck said:
Add me to the equation. 2017 Yamaha 115 with same issue…. Blowing seal and oil once 5k rpm are hit. Reset the seal and it did it again at less rpm. No service bulletin and mechanic had never heard of it happening. Has Yamaha come up with a resolution or is a class action suit on the offing?
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No solution from Yamaha that I know of.

I don't think the magnitude of the problem (number of failed oil seals versus number of F115's in service) does not rise to the level of needing a technical bulletin.

A class action suit for relatively few mechanical like kind problems on tens of thousands of motors? Shirley, you jest.
 
boscoe said:
No solution from Yamaha that I know of.

I don't think the magnitude of the problem (number of failed oil seals versus number of F115's in service) does not rise to the level of needing a technical bulletin.

A class action suit for relatively few mechanical like kind problems on tens of thousands of motors? Shirley, you jest.
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I jest but surely they’ve come up with a solution. Is installing the seal with loctite or a hold down plate an option? I’ve seen lots of complaints but no solutions. (And don’t call me Shirley…)
 
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