Backfire on decelerating?
Thread Starter
|
Cruiser
Joined: Jun 2010
Posts: 237
Likes: 25
From: St Louis
Backfire on decelerating?
2000 carbureted Fatboy is giving me some backfire noise on deceleration, particularly if I am going downhill and engine breaking. First time in 20 years I have had this issue. Took it into the shop and they replaced the exhaust and intake gaskets but no improvement.
Any advice would be appreciated. Thanks
Any advice would be appreciated. Thanks
Seasoned HDF Member
Joined: Nov 2018
Posts: 10,833
Likes: 6,485
From: Canada Flats
Exhaust baffles need to be repacked , perhaps your carb has gummed up and need a good cleaning , try running a couple tanks of sea foam through it , 1 once per gal .
How's the air cleaner ? A plugged / dirty air cleaner can cause a rich condition causing backfire . Intake leaks perhaps , bike at idle , spray some TB cleaner on them and see if the idle changes .
Clean the carbon out of the TB , tooth brush and some TB cleaner or sea foam will do , do the butterfly and seat as well .
Does your bike have stage 1 or just stock ?
How does it run / idle otherwise ?
How's the air cleaner ? A plugged / dirty air cleaner can cause a rich condition causing backfire . Intake leaks perhaps , bike at idle , spray some TB cleaner on them and see if the idle changes .
Clean the carbon out of the TB , tooth brush and some TB cleaner or sea foam will do , do the butterfly and seat as well .
Does your bike have stage 1 or just stock ?
How does it run / idle otherwise ?
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,076
Likes: 1,008
popping is caused by accumulation of unburned fuel in the exhaust. normally with a correct working carb, the fuel is too lean to burn on a decel and exits the exhaust with no issue. in this situation, extra air from leaks does nothing. but for grins and giggles, we add in extra fuel, still to lean to burn in the chamber, it will accumulate in the exhaust till it reaches a point where it can ignite and cause the pop. so have you reset the idle mix? is the throttle stop too far open? have you checked float height?
Trending Topics
Road Master
Joined: Oct 2012
Posts: 777
Likes: 45
From: Beaumont, Ca
Do you know what brand carb you have, and the number of the pilot/slow jet? Perhaps you might check if the pilot/slow jet needs to be increased to the next higher number to eliminate the lean condition.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
Jason Momoa Is Turning Classic Harleys Into PHEVs
Verdad Gallardo
Harley-Davidson Fat Boy Becomes a Dark, Decepticon-Inspired Custom
Verdad Gallardo
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Thread
Thread Starter
Forum
Replies
Last Post