Loose manifold

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Feb 21, 2023 | 11:57 AM

#11

OldMike

Seasoned HDF Member

Joined: Feb 2009

Posts: 5,642

Likes: 1,985

From: Cleveland Zoo

Quote:

Originally Posted by Jsndvll

Yeah, it's just loose when the air cleaner is off. But it kinda makes sense seeing how the manifold sits in the motor - there's nothing holding it bolted down really. Do you think i'll need new gaskets for the manifold or will i be good to go with the new air cleaner? I can't recall having any problem with it before i started picking the bike apart.

This is the point where I check and snug down the manifold flange screws. OR, like a lot of people do, get a SE 55mm manifold because of the bad things that can actually happen with the stock plastic manifold. Warping, leaking and cracking.

Feb 21, 2023 | 03:01 PM

#12

PureHybrid

Road Master

Joined: Mar 2013

Posts: 817

Likes: 380

From: Central Ohio

Quote:

Originally Posted by Jsndvll

When you get it fired back up, lightly spray some carb cleaner around those joints at the intake ports. If there's a leak the idle will change

Feb 21, 2023 | 03:10 PM

#13

chopper_man

Stellar HDF Member

Joined: Apr 2016

Posts: 3,330

Likes: 2,121

From: Masshole

100% normal. They require the air cleaner backing plate bracket and support to secure them. That is the anchor point to the motor/heads/rockers depending the bike you are working on.

Last edited by chopper_man; Feb 21, 2023 at 03:12 PM.

Feb 22, 2023 | 09:36 AM

#14

Since 1968

Road Master

Joined: Jun 2019

Posts: 952

Likes: 528

From: Richmond TX

My lack of memory on this was bugging me, so I went back to YouTube University and watched a manifold installation video. It's as chopper-man and 702 said, the movement is normal when the air filter or in some cases bracket is removed. However, the movement in your video is excessive, and about what mine was before installing the manifold backing plate for alignment purposes. With the tank still off and the backing plate (or support bracket for some) you then tighten the four screws (go ahead, call them bolts). If you were to remove the backing plate at this point there should be no sort of flopping around like your video. Based on all this, you probably don't need new rubber seals. I would try reinstalling and tightening and then checking for leaks. Go to YouTube and search for this: "install S&S 55mm manifold in M8"

Feb 22, 2023 | 08:32 PM

#15

propflux01

Road Warrior

Joined: May 2007

Posts: 1,434

Likes: 384

From: Arkansastan

Does anyone know, if you buy the aluminum manifold, does it come with the seals that mate the manifold to the cylinders, or do you have to order those extra through HD ?

Feb 22, 2023 | 08:49 PM

#16

mjwebb

Seasoned HDF Member

Joined: Jan 2008

Posts: 13,698

Likes: 11,492

From: State of Confusion

Quote:

Originally Posted by propflux01

Does anyone know, if you buy the aluminum manifold, does it come with the seals that mate the manifold to the cylinders, or do you have to order those extra through HD ?

https://www.harley-davidson.com/us/e...old/p/27300167

https://serviceinfo.harley-davidson....3?locale=en_US

Feb 22, 2023 | 10:09 PM

#17

Max Headflow

Seasoned HDF Member

Joined: Dec 2005

Posts: 19,957

Likes: 8,048

From: poway

Stock M8 manifold is plastic. It's not going to be held as tightly as a cast aluminum one.. Hopefully you wiggling it up and down has compromised the seal. Might be worthwhile to disassemble and inspect..