Serviced F150 returned with unusual noise

[TownsendsFJR1300]

Humor me, check to see if the engine oil is registering on the dip stick..

[paulwalter]

Engine oil is at the correct level on the dip stick and clean.

[pstephens46]

Many will upload the video to YouTube and then post a link here.

Don't leave us hanging......Another site for sharing videos....Vid.me

[paulwalter]

I put a short video on Youtube, "Yamaha F150 noise 7/2/17." When started cold, the engine runs with normal, quiet, 4 stroke noise at normal 700 rpms. Within about 3 minutes at idle, the noise you hear on the video begins. I can't describe the noise better than to say it sounds like an old car muffler or a diesel truck. Motor was serviced recently with tune-up, fuel filters, new water pump kit and oils. This noise began when I received the boat back from service. I'll put another video on Youtube of the motor when first started with normal noise. I'll also try to put the videos here but don't know how to, yet.

[99yam40]

just copy and past the web location at top of page
https://www.youtube.com/watch?v=7rBPVDfpsg0

[pstephens46]

My F150 sounds like this to a degree. I can't imagine what would have changed in the lower unit to make this sound appear. I don't know what would happen if the damper seal was not reinstalled....

Townsend - does your motor sound like this?

[paulwalter]

pstevens46: I wondered the same thing about the Damper Seal. Whatever is causing the noise takes a few minutes to build up. started cold the engine sounds normal (quiet) for about 3 minutes. When I increase the rpms at idle N from 700 to 14 or 1500 the noise seems to go away, and then back down to normal (700), the motor is quiet for about 1 minute and then the "muffler / diesel truck" sound starts. I have an appt Wed. with a different mechanic than worked on it last fall and this spring.

[paulwalter]

99yam40: Thank you for posting the video above.

[paulwalter]

https://www.bing.com/videos/search?q...08&FORM=VRDGAR

[pstephens46]

Were the plugs changed?

[paulwalter]

I assume the plugs were changed since there was a "tuneup." I could check them for fouling...would a fouled plug cause a noisy engine just sometimes?

[pstephens46]

I would just check to make they were torqued correctly. Trying to think of anything they may have touched. Did he give you an invoice with details?

[TownsendsFJR1300]

My F150 sounds like this to a degree. I can't imagine what would have changed in the lower unit to make this sound appear. I don't know what would happen if the damper seal was not reinstalled....

Townsend - does your motor sound like this?

There's really nothing down there, (WP), all the gears work properly, etc that would make that kind of noise short of the dampner being gone and the exhaust NOT dampened with water properly..

My 2006 F150 does NOT sound like that at all.

I had a video on Photobucket (flushing and idling on muffs and doesn't anything like that at all...

Photobucket is down/broke/who the heck knows..

If I had to guess I'd say (as others have) the dampner might have fell out or something. Mine is quieter than that OUT of the water on muffs..

I can make another audio / video but I have to find a new place to post, etc...

For the op, I seriously doubt it's ANYTHING CRITICAL, but would put $ is on that LU.

Her's a pic of my LU prepped to be assembled again but you can see the rubber strip (straight, black) just ahead of the exhaust. I suspect your's got knocked out of that spot.

Double click to enlarge:

[Reel Kahuna]

That's the exact sound that my '16 F150XB has. I just logged the 2 hr break-in. Guess I'll bring it to the Yamaha shop for them to listen to it. .

[TownsendsFJR1300]

Well, as PB is dead, the video is not available anymore.

I'll make a new audio / video tomorrow of mine on muffs idling. I should be able to post it tomorrow.