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.

 

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

 

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.

 

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.

 

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

Try that!