Backfires on deceleration

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Jan 27, 2015 | 11:10 AM

baukienvn

Thread Starter

Stage I

Joined: Jan 2015

Posts: 1

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From: hanoi

Backfires on deceleration

My Harley Davidson heritage softail has an annoying backfire from the rear cylinder when I let off the throttle on the freeway or when I'm coming to a light. I just had the top end rebuilt completely rings valves heads refaced etc plugs are new exhaust system is tight no leaks. Now the bike is only 4 years old but I do have 99k on the motor.. Any ideas??

Jan 27, 2015 | 11:45 AM

upflying

Seasoned HDF Member

Joined: Aug 2013

Posts: 35,798

Likes: 38,564

From: Post Falls, ID

Wow, a Vietnam Harley. Welcome to the forum!
Maybe a mod can move your post to the appropriate discussion room, "off topic" is not correct.

Jan 27, 2015 | 11:53 AM

RAWHIDE07

Seasoned HDF Member

Joined: Jan 2008

Posts: 52,957

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From: SW OH.

Possible intake manifold leak.

Jan 27, 2015 | 12:05 PM

Hippie49

Elite HDF Member

Joined: Dec 2013

Posts: 4,018

Likes: 231

From: Kentucky, USA

Quote:

Originally Posted by RAWHIDE07

Possible intake manifold leak.

Would be the first place I would look.

Mine was doing the same.

Applied some thread locker and torqued to spec. and all is well.

Jan 27, 2015 | 04:48 PM

hollowpoint

Elite HDF Member

Joined: Oct 2007

Posts: 3,605

Likes: 3

From: Adirondack Mountains

You better take it to an authorized Harley Davidson Dealer.

Jan 27, 2015 | 04:53 PM

Gliden

Club Member

Joined: Jun 2009

Posts: 5,323

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From: NJ

After all that work....give it to a tuner and tune it out and maximize all the work you had done. I had annoying decel pop after 106 job was done. I pin pointed what Rpm's on decel and what speeds it happened at, told my builder/tuner....he dialed it out.

Once in a while I get a pop or two but not like the machine gun popping I had after the build.