Finally got around to rejetting my ninja. I recommend rejetting since ninjas come out of the factory lean, and lean out further with slip-ons, etc. I figure people may be able to use my settings as a good reference for what they might want to do with their bike.
If your planning on rejetting your ninja, seriously consider K&n filter pods. They cost about 60$ shipped and not only make your bike perform better, but made the rejetting job much easier. They get rid of the stock airbox which is a real pain to remove or put back in I would imagine.
The Dynojet kit cost about 90$ shipped which made the grand total for this 150$ for a more reliable, better running bike. After about 4 hours install time and more like 6 hours tuning time, I ended up with these settings:
DJ114 Main Jet
Needle Jet @ position 5 from top
Idle mixture screws 4 turns out
It pulls so much better through the entire rpm range. Bike runs much better cold. There is no more gurgling at cruise between 5000-7000rpm. The spark plugs come out clean!! Also you get the peace of mind that you aren't roasting valves every time you accelerate.
Be prepared to do lots of fine tuning....i tried 3 different configurations before it came out right. The needle height & Idle mixture were the most tedious to work out, but both can be adjusted while the carb is still attached to the bike.
If I were reading this I would want to know that Factory Pro has a kit that comes with the filter pods and a better jet kit. That jet kit will have more main jets to choose from, rather than just the ones they recommend like the Dynojet. Its also nicer getting both the pods and the kit all at once so you aren't pulling your hair out because you have one and not the other.
2007 Ninja EX250F
- K&N Filter Pods (RC-1822)
- Dynojet Stage III Jet Kit
-DJ114 Main, Needle Pos. #5
- Full Yoshimura Exhaust
- 47-tooth Sprocket