Yamaha f114 four stroke noise at WOT

[efdog]

First off, I apologize for posting about a random noise, as I know they're difficult to diagnose in words. That being said, here goes. I just acquired a 2007 f115 that seems to run fine. WOT is approx 5800-5900 with a 13.25 x 17 prop. My issue is that there is a whirring, sort of a squeal with throttle is wide open, even at lower RPM's (getting out of the hole / onto plane). If I back off the throttle even slightly the whine / whirring / slight squeal goes away. Excuse my ignorance as this is my first four stroke, so my terminology may be way off here, but it's as if once the engine is running on all cylinders then I hear the noise.

Any help is greatly appreciated as to what this may possibly be.

Cheers

 

[T_Herrod]

Re: Yamaha f114 four stroke noise at WOT

it's as if once the engine is running on all cylinders then I hear the noise.

Any help is greatly appreciated as to what this may possibly be.

Cheers

Your engine should be running on all cylinders as soon as it starts. Is the noise coming from the engine or could it be from something in the lower unit?

 

[efdog]

Re: Yamaha f114 four stroke noise at WOT

Your engine should be running on all cylinders as soon as it starts.

Ok, so is it possible that it's not firing well on one of the cylinders? Would this cause any other noticeable issues aside from the obvious loss of power?

Is the noise coming from the engine or could it be from something in the lower unit?

Yes I'm quite certain the noise is coming from the top end.

 

[T_Herrod]

Re: Yamaha f114 four stroke noise at WOT

How's your compression? I it possible there could be a leak in a vacuum hose or manifold gasket?

 

[efdog]

Re: Yamaha f114 four stroke noise at WOT

I didn't check compression personally. Dealer I bought this from last week told me compression was good. I'll be getting my own compression check done on Wednesday. Hoping it's not a ruined engine. It could very likely be a hose issue, air leak issue. My initial reaction when I heard the noise was that it was wind passing through the cowling oddly. The sound can actually be best described as that eery sound of wind passing through a small crack in a window on a stormy day

Thanks for your help, this gives me something to go look for.

 

[T_Herrod]

Re: Yamaha f114 four stroke noise at WOT

Try taking the cover off and running it. Have someone drive and you could listen for the noise. Just be very careful not to fall out of the boat.

 

[efdog]

Re: Yamaha f114 four stroke noise at WOT

Try taking the cover off and running it. Have someone drive and you could listen for the noise. Just be very careful not to fall out of the boat.

That's my next course of action. I'll update on the results

 

[Capt Ken]

Re: Yamaha f114 four stroke noise at WOT

Whining noise from the flywheel area is normal. There is a bushing on the drive shaft that has to be greased once a year but that requires dropping the lower. It will whine also if it gets dry.

 

[efdog]

Re: Yamaha f114 four stroke noise at WOT

Whining noise from the flywheel area is normal. There is a bushing on the drive shaft that has to be greased once a year but that requires dropping the lower. It will whine also if it gets dry.

Wouldn't the bushing issue, or flywheel noise be contstant? I'm only getting noise at WOT, and not RPM specific. I back off the throttle and noise is gone. I'll be getting it back on the water Wednesday, so I'll have some more info then.

 

[efdog]

Re: Yamaha f114 four stroke noise at WOT

Got out with mechanic yesterday. He said that the noise is just air suction and that it's normal. Anyone else with these motors finding this? It could also perhaps be echoed and seem louder than what it actually is due to the shape of my boat (dual console triumph). The noise was actually much much less noticeable when sitting directly next to the motor. Anyway, though I would provide this update.

 

[Triton II]

Re: Yamaha f114 four stroke noise at WOT

Ran an 09 F115 for a little over 500 hours and it had cam-belt whine at 3800 and a hum like blowing across the mouth of a beer bottle at WOT. Perfectly normal apparently.

TII

 

[Larry3215]

Re: Yamaha f114 four stroke noise at WOT

I have a new F115 and it makes a whining type of noise between 1000-2000 rpm. The mechanic thought it was the bushing, they lubed it and it was still there. He then took a ride with us and said it sounded like exhaust noise and was "probably" nothing to worry about. he suggested we change props and see what happened.

We were running an after market prop when it made the noise. After switching back to the stock Yamaha prop - no noise. back to the after market prop - noise.

No we plan to try a different prop to see if that helps. The stock Yamaha 13x19 has too much pitch. the aftermarket 13.25x17 is about right - except for the noise.

I forget which after market prop we have. I think its one of the cheaper Mercury brands?