Hey guys,
My buddy last week had an issue with his 2018 Ultra Classic and took the bike to his local dealer. They replaced a lifter and the cam as the lifter had scored it. assorted gaskets and such as well. He rode it home, about 15 miles, and when he shut it down, he heard a strange noise that he described to me as "a weak bagpipe losing its air|, lol, It only happens when the bike is warmed up. I can wrench on my own bike, but ive never heard this sound before...
Thoughts? see the vid and listen for the noise at the end....
Thanks

 

Take it back to the dealer that did the work. Once you start messing with it yourself, you have no comeback.
Could be as simple as engine breather wheeze. Are the hoses all connected back up? Or it could be something else. Head gasket would more likely make noise under power.

 

Definitely... He called me about an hour ago as I was writing this and was at the dealer already. So far, no answers yet.

 

Hopefully the dealer figures it out and fixes it. With something like this it is important to notice if the noise stops at the same time the engine stops rotating (a mechanical noise) or if it continues briefly after rotation has completely stopped, likely pressure bleeding off from somewhere. It could even be some sheet metal vibrating briefly after the engine stops

 

It continues after the engine has stopped moving. i was thinking a pressure relief thing too... I just got another call from him... HD tech says its a normal noise... LOL. Seriously? i'm waiting for his response to that decision.

 

It’s crankcase vacuum releasing after shutting down. Normal.

 

OK, I have to admit I'm not all that good with the M8's... but my buddy told me that it did not make that sound before the valve and cam were replaced. They did upgrade the cam to a SE cam of some type.

 

There is a thread about this somewhere. It's normal, mine does it as well. After you shut the bike down, it becomes the Sad-Glide...

My bike has a cam too... maybe the valve overlap something.

 

When you shut the motor off the throttle valve closed since there isn't any synchro power.. With the motor coming up on compression on one cylinder, it fails to make it over TDC and rotates backwards. That causes intake valve to open and pressure causes the throttle blade to vibrate making a bagpipe sound. I doubt it a breather as the sound has to travel down a passage and the throttle valve is closer to the intake and has a bigger hole to make the sound. My 17 RK does it occasionally. It's nothing to worry about.

 

Could be the pressure leakage going past the rings on a partial compression stroke when shutting down. One time on a former Harley, I went to check the oil right after shutting down and a there was a big suction release when I removed the dip stick cap. Only happened once, but maybe I’ve never checked it so soon after shutting down. The breather passages in the intake do create a vacuum in the crankcase, provided there’s not a lot of blow by.