hey all . im new to street bike riding and so i just bought a ninja 250. first thing i noticed was that the bike would fall on its face after about 9500rpm and wouldnt rev past 10k . keep in mind im at an elevation of 5,622 ft and the baffels are taken out of the exhaust with stock air box. my ninja felt like it was starving for fuel so i took out the 105 main jets and installed 110 mains and it ran even worse.so what i was wondering is if i should go smaller on the jets? this bike runs so bad that a 150cc moped could kick its ***. and for sure its a fuel problem. so if anyone has any tips i would would be very greatfull . if this thing cant hit the red line its worthless IMO. i have jetted many dirtbikes with mains and a needle adj. with no problem but this is a completly different animal lol . please any help would be great.

 

tip? um buy a bigger bike.....

 

Well air is thinner at higher alt. So you would need to take fuel out not add it. With going with a bigger main jet I bet your flooding the cylinders with way to much fuel. Why don't you pull the sparkplugs and see what they look like. If there is a butt load of carbon and there all black your running way to much fuel. Put the stock jet back in and get on it a few times after the bike is warmed up the let it cool off and pull the plugs and see what color they are. If there more brown it's running a lot better. But yea a 250cc @ 5000ft problably is kinda slow.

 

well i dropped some 98 mains jets in and omg what a impressive little bike. i can hit the rev limit no problem now and it pulls very hard from 6-14k and i checked my plugs and they are perfect. no spits or sputters of any kind. very pleased with the results. i knew there was more in that 250 engine lol

 

the 250 is a trainees bike its not a boosa, if your looking for speed go up in the cc.

 

Congrats on figuring out your jetting.

 

thanks it runs great plenty of pep for me atm. i have put about 50 miles on the new jetting and im impressed with the pick up that little bike has for the size when running right. its no slouch.

 

Wow... your whole outlook on life seems to have been changed for the better. See what great therapy a good running Kawi is? Glad you got it sorted out.

 

he needs more therapy, he keeps looking down on the 250 calling it little....

 

It is little. That's not a bad thing though. The whole engine is the size of one of my wife's cylinders, and her bike is still little. I'm just a little freaked out that he fixed it before I could suggest hitting it with a hammer!