The Dyno Room A special room dedicated for Dyno tuning products, troubleshooting and results. All Gearheads and Dyno Operators are welcome here as well as the guys that are new to tuning. Please see the special rules for this section before posting.

Other Devices: 07 FXDB with Fuelpak running lean?? Backfiring regularly

Thread Tools
 
Search this Thread
 
Old Jul 12, 2010 | 12:26 PM
  #1  
eric.west's Avatar
eric.west
Thread Starter
|
5th Gear
Joined: Sep 2008
Posts: 9
Likes: 0
From: South Central KY
Default 07 FXDB with Fuelpak running lean?? Backfiring regularly

Ok, heres my settup. I have a 2007 Street Bob with a stock 96. I'm running with Vance & Hines Black Short Shots, an Arlen Ness Big Sucker and a Vance & Hines Fuelpak. I installed this myself about 2 years ago and was very pleased with the settup. I found increased power as well as increased fuel mileage from the changes.
The bike now has just over 18,000 miles and has its regular service done by my local Harley Davidson Store. The last service was done about 1500 miles ago, with a return recently due to oil from my breather (Im afraid they may not have checked everything I paid to have checked, but I'm overlooking it this time as they corrected the situation at no expense to me).
In recent months however, I've noticed excessive backfiring and misfiring. Sometimes at start up it hesitates. Very often when shifting it backfires. And pretty much every time I'm downshifting to slow it backfires and pops. I've just checked my plugs and found them dusted white, so I'm sure I'm running too lean. I've double checked my settings on my Fuelpak to assure something hasn't changed.
I'm wondering if the exhaust opening up over time, engine break in or anything else may factor into the need for remapping. Everything I'm seeing from Vance & Hines pitches how they have everything mapped out for you with no need for change, but I must wonder.
I've heard of the various other fuel control systems on the market and the ease of adjustability of some of these systems. But my Fuelpak did very well initially and hope to spare the expense of buying a new settup.
Does anyone have any proven map values for the Fuelpak for my specific settup? Or know of a way to retune my current settup? Would a qualified mechanic be able to remap this settup accordingly if the bike was on a dyno?
Any help or adviced is greatly appreciated.
Thanks, Eric.
 
Reply
Old Jul 18, 2010 | 07:40 AM
  #2  
AFHuey's Avatar
AFHuey
Cruiser
Joined: Jun 2009
Posts: 194
Likes: 0
From: England
Default

If it was working before without decel popping or backfiring, then something else is up. Mine, started like that out of the box. After changing exhaust gaskets many many times at the behest of V&H, I finally gave up. You will see that I am not a proponent of the FuelPak.

My advise to you, if you had no issues and this just started developing, then search for the cause. Could be that your exhaust has come loose, is leaking or heaven forbid....cracked. A decel backfire is different to popping. One is an enriched condition and the other is a lean condition.

I wouldn't mess with the settings if they worked for you. I'd focus on something mechanical that has changed....(read exhaust leak).

Just my $.02
 
Reply
Old Jul 18, 2010 | 08:03 AM
  #3  
nevil's Avatar
nevil
Seasoned HDF Member
15 Year Member
Liked
Loved
Community Favorite
Joined: Jul 2008
Posts: 9,282
Likes: 1,139
From: southeast PA
Default

Look for exhaust leaks, check the muffler clamps and the flange nuts on the heads. These tend to loosen up.
You also want to check for intake leaks. My intake seals failed early on. With the motor running and warmed up, spray some carb cleaner directly on the intake flanges, one at at tim. Do this from the right side so it won't go into the a/c. If your idle changes you have a leak there.
 
Reply
Old Aug 1, 2010 | 11:07 AM
  #4  
eric.west's Avatar
eric.west
Thread Starter
|
5th Gear
Joined: Sep 2008
Posts: 9
Likes: 0
From: South Central KY
Default

Checked for exhaust leaks and have none. Checked clamps and bolts to be sure everything was snug for good measure.
Shot an email to V&H with the same question and a rep told me to send him my settings. So I did (which are the ones as stated in my instruction sheet) and never heard back from him. Guess he figured since it was set right there was nothing he could do for me.
Just figured with all the different settings for the different bikes in the paperwork that came with it, one of them would enrich the fuel just enough to keep the bike from running lean. Dont want to burn the pistons and begin to have engine problems from it.
Have talked to several who have alternative fuel systems with the ability to remap it from their home computer, or put it on the dyno and really tune em in. Looks like there orta be something that could be done safely.
I do appreciate the help.
 
Reply
Old Nov 22, 2016 | 12:42 PM
  #5  
jamalhussein's Avatar
jamalhussein
Intermediate
Joined: Oct 2016
Posts: 31
Likes: 2
From: NAIROBI
Default

My iron had the same issues. I managed to sort it out... disconnected the Vance and Hines fuelpak and bike performs sweeeeeeeeeeeeet

Try that!
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
blackflame
Touring Models
15
Jun 25, 2013 09:57 PM
2manytoys
Touring Models
14
Jun 8, 2013 04:21 PM
201048
Dyna Glide Models
8
Sep 16, 2012 03:53 PM
fitpays
Dyna Glide Models
5
Apr 27, 2007 07:59 PM
Roodog
Exhaust System Topics
11
Feb 18, 2007 12:55 AM




All times are GMT -5. The time now is 09:00 PM.

story-0
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-1
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-2
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-3
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-4
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-5
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-6
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-7
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-8
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-9
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE