s the saying goes “There’s no replacement for displacement,” and these days big-inch V-twins are all over the place. Fuel-injected versions. There’s one little tuning wrinkle that comes into play regarding these big-inch engines and their fuel/air requirements, though, and it happens during the Start-Up Cycle. In cooler weather that big-inch bike with its bigger-than-stock injectors running under higher-than-stock pressure might struggle a bit to get running. The heat sensor is telling the ECM that the bike is cool and, understanding that information, the ECM automatically richens the injectors up accordingly. And with those bigger injectors it’s too much. What’s needed here is a separate adjustment feature for the Start-Up Fuel, something to let you dial that start-up fuel delivery back just a bit.
     The newest Power Commander III USBs have it, along with another useful feature, too. This one is the Rev X-tend, a simple adjustment allowing a PC III-equipped Harley-Davidson (V-Rod excluded) with a stock ECM to now rev all the way to 6,200 RPM. There’s no need to have that ECM re-flashed at a dealership to gain full control over your fuel curve, and no need to install the Harley “Stage 1 or 2” upgrade (spending an extra $150-$200).
Both of these adjustment features can be enabled on the latest Power Commander III USB units with part # 801-511, 802-511, 805-511, 807-511, 810-511 and 811-511. To enable the features on earlier units will require a firmware update, but that’s no problem. The fastest and easiest method is to get the $40 firmware programmer and the necessary software which will let you update an unlimited number of units, or you can send an individual unit directly to Dynojet and for $20 they’ll enable the features and return the unit to you.
Accessing and adjusting both Rev X-tend and Start-Up Fuel is quick and it’s easy.      Everything is right in the Power Commander Control Center software, version 3.1.3 or newer. While the software is communicating to the PC III hit just CTRL-F on your keyboard bringing up a window called “Power Commander Features Dialog.” Check the box next to the feature you want to enable. When you check the Extend Redline feature you’ve just raised your bike’s rev limiter to 6,200 RPM and if you ever want to turn this feature off just un-check the box. A different RPM setting can’t be entered.
     Checking the Start-Up Fuel adjustment box gives you the ability to richen or lean the fuel mixture during start-up without affecting anything else in the base map. This is the feature so needed with those big-inch/highly modified engines that have a hard time starting when cold. To adjust the settings here go to POWER COMMANDER TOOLS–START UP FUEL where you’ll find two fields to adjust. The first field is the Percent Of Fuel to add or subtract during start-up. Inputting a value here will offset the fuel by a given percentage above and beyond the stock ECM and Power Commander. The second field is the number of engine revolutions (or time) that this feature will be active for. A normal value would be around 150.
     That’s it. Easy adjustments needed by all those big-inch hot rod Harleys on the road. The newest Power Commander III USB models, the ones currently in the warehouse, already have these adjustment features available. If the serial number (shown in the upper right corner) is higher than 060201000001 the upgrades have already been installed. That firmware programmer can take care of all the others, so check with your Drag Specialties rep.