Jet Kits

All riders, not just racers, benefit from having a properly carbureted bike. While an aftermarket pipe may make your bike more powerful, making sure the carbs are properly jetted will result in more power and improved power delivery--whether you have a hot pipe bolted on or not. For example, getting optimum power and smoothness out of an inline-four may require different needle or jet settings for the center carburetors and the outer ones. Often, once the needles and jets are set correctly for all the carbs, a bike wakes up, producing more horsepower in the midrange, revving quicker and sounding significantly smoother.

Even on bikes with stock exhausts, the midrange can be overly lean, making acceleration in the range streetbikes spend most of their time feel soggy. Simply raising the needles a bit will solve this problem. So, don't think you only need a jet kit for piped bikes. If you have any problems with your bike's carburetion, consult the aftermarket. A fix is probably available.

Fuel Injection Remapping
When sportbikes began to arrive in showrooms with factory fuel injection, changing a bike's mixture was significantly more difficult than with carburetors.

Now that the aftermarket has had a few years to develop some solutions, you can buy systems with alternative injection maps for both stock and modified bikes. For example, systems like Dynojet's Power Commander and Yoshimura's EMS come preprogrammed with fuel delivery curves for your bike. Both fuel injection modules will also allow you how to alter these curves in the low-, middle-, and high-rpm ranges through the use of buttons on the u

The real power, however, lies in computer software that allows for control over fuel flow in increments as small as 500 rpm. This is the ultimate tinkerer's tool! Also, many shops that offer dyno tuning also have computers that can upload maps specific to your bike's characteristics after dyno testing.

These magic boxes don't just offer EFI tuning, though. The Yoshimura EMS connects to an accessory hub that can allow the rider to switch between three fuel curves while riding or install a shift light or ignition-related accessories. Similarly, the Power Commander features an expansion port for other modules that are being developed.

These Factory Pro Tuning velocity stacks bolt either into the airbox or onto the throttle bodies to massage the horsepower output.

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