My 2009 Ninja 250R currently has the following engine modifications...
• Yoshimura TRC Slip-On Exhaust
• Dynojet Stage 2 Jet Kit
• K&N High Flow Air Filter
I had these parts installed by my local dealer, who does not have a dyno, so they jetted the carb to get the bike running properly, but were unable to tune it for any type of performance. A few months after having the parts installed, I decided I wanted to have the bike dyno'd and then tuned appropriately, so I took it to MPHOhio where it was tuned on their Dynojet Dyno.
Stock 2009 Ninja 250R Dyno Chart - click to enlarge
Shown above is a stock Ninja 250R dyno chart. This chart is not for my personal bike, but another 2009 Ninja 250R that the shop had just done a base dyno run on a few weeks prior to working on my bike. As you can see, the stock bike has a peak horsepower of around 25 (at around 10,000 rpm) and a peak torque of around 13.50 (at around 8500 rpm).
My 2009 Ninja 250R Dyno Chart - click to enlarge
Shown above is the dyno chart for my 2009 Ninja 250R with the Yoshimura TRC Slip-On, K&N High Flow Air Filter, and Dynojet Stage 2 Jet Kit mods. MPHOhio did a base run on the bike with the silencer/baffle I had installed in my Yoshimura TRC slip-on. I then had them remove the silencer/baffle before tuning the bike. They made a few carb changes and the bike ended up with a peak horsepower of 28.44 (at around 10,500 rpm) and peak torque of 15.02 (at around 7000 rpm). The bike runs great and seems to pull better down low than it did before. The powerband seems to be a little smother as well. I really like the end result. Overall, the modifications I had done to the bike added about 3.44 hp and just under 2 lb-ft of torque (compared to a stock Ninja 250R).
What I learned from this is how important it is to have your bike properly tuned on a dyno once you do any type of engine modifications like adding an exhaust, hi flow filter, and jetting your carb. I've read about many riders trying to do this stuff themselves and they end up with bikes that are not tuned to take advantage of the new modifications, and in some cases their bikes don't run as well as they did prior to the modifications. Without a doubt, the best way to do it is to have the bike dyno tuned by a qualified shop.
