Good cannot describe the rating for this product I have an 04 250X that had a bad case of the bog and with the mods I did the bog only got worse. I bought the kit being sceptical and installed in. I can only say that I was totaly blown away by the change in my bike the low end power gain is nothing less than increadible, the bog issue I had is gone. This is the best money I spent to bring out the performace of the 250X, it is like having a brand new bike.
Bought my 2004 crf250x and it had sat awhile. It had some bog under hard acceleration. I bought this kit and a boysen quickshot 2. All problems are gone. It runs great and is such a fun bike now. Highly recommend.
I installed the jets and needle per JD instructions on a new 2012 CRF250x and WOW it made a HUGE difference in how it runs. It starts easily, idles smooth and rips! First I cut out the top of the air box under the seat with a heated utility knife, then installed a Yoshimura RS2 slip-on pipe. I was going to have the Honda shop install the jets but couldn't wait so I decided to give it a try and it was actually pretty easy to do following the "how to" article and JD instructions. Money well spent.
I went with a 160 main, the red needle recommended for my area, a K & N airfilter, drilled out part of the baffle in the exhaust and opened up the top of the air box as recommended by the crf only representative and per the instructions in the JD kit. The bike starts easier, has way more pull, and is not near as cold natured as it used to be. The kit was easy to install and worked straight out of the box with no other adjustments. Worth every penny.
This is a very nice kit! Comes well packaged in a storage box with clear directions. It really wakes up the bike. I was running the NCYS needle and such, but this kit works better and really made a difference with the FMF Q4 exhaust.
This kit is pretty sweet, i bought it for my FMF system so i dont run to rich and when you have set right it works amazing, the down side is that you have to cut a hole on the of the air box, for the 2008 CRF250X's anyways, this is bad because if you right in a dusty place like i do your air filter gets dirty pretty good. Also is does increase your throttle response.