IMO, I doubt that.. I've there will typically be any kind vacuum in the crankcase if the motor tops anywhere besides where the pistons are close to bottom of the cylinders.. What is the mechanism for the squeak?? I doubt it's the rings. How are you going to hear it?

 

The only thing that I can think of that could make a squeaking noise is the umbrella valves up top. I know that a reed valve will make a weird noise at times and that’s basically what an umbrella valve is; a one way valve. I was referring to a hissing noise regarding pressure going past the rings. Open the oil cap and bump the starter quickly….it’ll be there.

Edit: I missed that there was a video file of the noise…just listened to it. I’m going with umbrella valves letting crankcase pressure out.

 

So here’s a weird addition……my 22 RKS did it all the time on shutdown. I added an Arlen Ness Big Sucker air cleaner, and got a PV3 from FuelMoto. Did their tune and an autotune……now it doesn’t do it anymore. Hoodaf#ck knows…….

 

Thank you, guys... I'll be passing all this info to my buddy. We live 5 hours apart so it's hard for me to see and hear exactly what's going on... but the suggestions your guys have come up with are much appreciated. I think he needs to get on this site as well, lol.

 

My 2022 did that initially for first 8000 miles than it stopped. I consider it normal. I agree pressure going out from somewhere. While I have no idea where it came from exactly my guess was it might be pressure escaping heads if valve is slightly open or he's mentioned earlier umbrella valve maybe. Tell your buddy not to stress about it.

 

My stock 2021Road Glide makes the same wheezing noise when shut down. The bagpipe description is the best I’ve heard. It sounds like two different pitches - like you dropped an accordion on the floor and the air wheezed out for two seconds. I do have the breather dipstick.

 

I have 2020 SG Cvo with not even 3500 miles yet and mine does this… sounds like Whoo…as something spooling down. Dealership said normal and will happen often and noise is out of high flow air intake. I believe he’s right.

 

Try this, Just as your are about the turn off the bike, unscrew the oil did stick to equalize the pressure and then turn off the bike. If it does not do make the noise then you have confirmed the dealers statement.

 

Tell your buddy to relax, same here on 2022 RKS with 10k miles. Mine does same thing from the moment it was brand new and I agree with this post above I strongly believe is is air leaving heads through slightly open valve probably. I consider this normal engine sound saying to the rider “we are done with the ride already?” = sighs pssss 😁

 

My 21 does it most of the time, it's as sad as I am the rides over!