MXA WRENCH TECH: HOW TO REPROGRAM YOUR 2010 THRU 2013 YAMAHA YZ450F EFI MAPS:

MXA has provided four maps (in the tables included in this article) that we liked during our testing (and we still make changes on a daily basis for different test riders). These maps don’t come with the GYTR Power Tuner. As it comes out of the box, all the fields in the GYTR Power Tuner are set at 0, 0, 0, 0, 0; which are the stock ignition and fuel settings. When you move the cursor to a specific field within the fuel injection grid, you can change the value to whole numbers between negative seven and positive seven. Each number is an three percent change. So, entering a “+7” makes the bike 21 percent richer than the stock 0 setting in that performance area. The ignition map either retards (-) or advances (+) the ignition by one degree per whole number (entering a -5 retards the ignition five degrees).

Our four maps are useful starting points for creating your own maps. Our best method was to ride the zeroed-out stock map first, then install one of our homemade maps that matched our desired change (it is important to note that you can change both the ignition timing and the fuel flow (or only one of them if you wish). After riding both, it was easy to determine what part of the powerband we wanted to make values closer to zero, and which part we might like to go further. For example, most MXA test riders preferred to race with the “Less Hit” map, but test rider could change the values to fudge towards the stock curve or away from it. The barky low-end was the major complaint and the “Less Hit” map irons it out.

IS THERE REALLY A PERFORMANCE GAIN?

The million dollar question is “How much does the Power Tuner improve the performance of the bike?” The answer is not cut-and-dried because we made maps that made the power worse, maps that moved the power around, but no maps that actually made more peak horsepower.

Different maps can substantially change the feel of the power delivery. They can even make small changes to where the power is situated in the powerband. Depending on your sensitivity, different maps can make the bike feel a little quicker, more sluggish or easier to ride. Different mapping cannot, however, add power and make the stock bike faster (that is not 100 percent true, because we could lean everything out and gain horsepower…we just don’t know for how long). Truth be told, the stock bike runs really well. The real benefits of the Power Tuner come into play when you hop the engine up, raise the compression and switch to different types of race gas.

The average Joe (with a stock engine) can tune the powerband in to his tastes. That is a plus.

MXA’S GYTR POWER TUNER MAPS