I have a similar post on the Sportster page, but thought that this might be a better place to post my results/experience.

I have experienced Stage 1 success with my EFI sporty using the Screamin’ Eagle Race Fueler (HD part 32173-07) or SERF. This post is to help first time users set up their SERF quickly.

First, why a SERF and not a remap? The cost is about the same, but the SERF allows you to “tune” the bike to your needs and modifications. You can lean out 10% or richen up to 40% for each rpm range. You can also change the crossover points and change the “accelerator pump” 0-100%. It is like having a parts-bin full of carb jets, but takes only seconds to change settings.

Downsides? The instructions for installation are OK, but my dealer was worthless when it came to setting this thing up. However, with the help of the Big Twin guys on another forum, I have dialed-in the SERF and am very pleased with the results. I hope my findings will encourage some additional tuning dialogue for those using a SERF or similar devices, such as the FuelPak.

Installation: The unit is plug into the existing wiring harness. Install the SERF (about the size of a lighter) on the battery bracket behind the battery cover using the enclosed Velcro. It fits perfect. Run a ground wire under the seat (the ground point to use is obvious). Run the wires in such a way as to ensure they do not touch the engine. The kit includes the ties to keep the installation neat and OEM appearing. The great thing about this kit is that it can be removed and no-one will know it was ever there!

Tuning: The dials (potentiometers or pots) on the SERF are oriented as follows.
| 1 |____| 2 |____| 3 |____
Red LED Yellow LED Green LED
| 4 |____| 5 |____| 6 |____

R = Red LED Low rpm range Y = Yellow LED Mid rpm range G = Green LED High rpm range

What each dial, or pot, does:
1 Low rpm range fuel adjuster ______ -10% to +40% fuel correction
2 Mid rpm range fuel adjuster ______ -10% to +40% fuel correction
3 High rpm range fuel adjuster _____ -10% to +40% fuel correction
4 Low to Mid rpm cutover range _____ 900 to 3500 rpm
5 Mid to High rpm cutover range ____ 4500 to 7100 rpm
6 Accelerator fuel enrichment _______ 0 to 100%

The dials are marked 0 to 10 0 = Fully Anti-Clockwise position on all dials 10 = Fully Clockwise position on all dials. For example Position 2 on Dials 1, 2 & 3 roughly equates to no fuel correction. My unit was factory set from 0 to 2, meaning the bike ran poorly before changing the settings. Do not worry about that, and once installed, go for a ride to warm the bike up to full operating temperature. Now, take off the battery cover, open the SERF using a very small Phillips screwdriver (the same one you will be using to adjust the pots) and let the fun begin.
Dial #____Position
Dial 1 ___ 3
Dial 2 ___ 3
Dial 3 ___ 4
Dial 4 ___ 3 - (Low to Mid rpm needs to be set at around 2000 rpm which is about setting 3) \
Dial 5 ___ 0 - (Mid to High rpm needs to be set to 4500 rpm which is 0 on the dial)
Dial 6 ___ 5

Now, Take it for a short ride. Better, eh? Actually, it should be much better. Now, for the REAL fun. Fine Tuning.
Dial 1: Start the engine up and slowly increase the rpm until the red led goes out (about 2000rpm) and the yellow led comes on then bring it down a bit until the led's swap back over and we have the red one lit again. You need to hold this rpm really steady (now you can finally use that throttle lock on the handle bar). Now very slowly increase dial 1 (clockwise), the engine should start to speed up (if the yellow led comes on then set the throttle back a little so we are back on red). You will get to a

 

Hello.I am new to the forum.I found it doing a Google search. My question is how much modification can I do to my 883 Sportster with the HD Race Fueler.I have an 08 Sportster Low.I am planning an air cleaner change,slip on mufflers and later a big bore kit.Any info will be appreciated.Also,is the race fueler better than a power commander?

 

What it comes down to is this. What ever you choose be it PC III , V/H Fuel pak, SERF or anyother device.None of them or real power gainers. They all or band-aids. Just covering up a under lying problem. I found a screamin eagle race fueler for 100.00 off e-bay deleivered. I installed it myself . Dealer dyno it for 70.00. I can put up hp numbers that will match any PC III equiped bike. So choose what ever you feel comfy with. If you not going to do a lot of motor work find the easy way. IF you going to dig into it. Go with SERT.