Now that carburetted motorcycles are becoming a thing of the past, the Dynojet Power Commander has become the ubiquitous tuning accessory.
It's the cheapest and easiest way to tweak your fuel injection – whether to match a replacement exhaust, or simply to clean up the fueling on a stock motorcycle that's running a little rough.
Simply put, the Dynojet Power Commander sits between your motorcycle's ECU and the injector units, and can adjust the electrical signal going to the injector at certain rpm and throttle openings. So if the motorcycle manufacturer has made the fueling a little weak at certain engine speeds, to suit exhaust emissions requirements, a skilled dyno operator can program the Dynojet Power Commander with an appropriate correction factor. The ECU sends a signal out telling the injector to open for a certain time, but the Dynojet Power Commander intercepts and tweaks the signal, making the injector open a little longer. You get a richer, better-matched fuel/air mixture, and better running. The same changes apply if you've fitted an aftermarket exhaust. Most will be designed so that your engine runs pretty well without any changes in fueling needed. But even then, a skilled dyno fixer will be able to more-accurately tweak the fueling with a Dynojet Power Commander. The dyno uses an oxygen sensor in the exhaust to 'sniff' the gases, giving indication of a rich or weak mixture, and watching this sensor allows the operator to modify the stock injection settings to suit the new exhaust pipe.
At between 11,000 to 15,000 THB, the Dynojet Power Commander isn't a super-cheap modification, and you'll need to add on some dyno setup time. But if you're making any other changes to the engine, particularly and exhaust, the Power Commander is pretty much essential. And even stock motorcycles can have their fueling tweaked to improve rideability. To check if there's a Dynojet Power Commander available for your motorcycle...