What is the best tool to use when trying to turn the fuel screw? My bike is really running lean and I need to make an adjustment but just cannot get at it.

You probably figured it out by now but to adjust your fuel screw you'll need either a flat blade screwdriver that's shorter than I've ever seen, a fuel screw tool like the ones on these pages http://www.sudco.com/tool.html#950-406 , http://www.holeshot.com/tools/ or you can bite the bullet and replace your stock fuel screw with an adjustable one from Scott's or Factory or Zip-Ty or Kouba or any of the others out there.

Thanks for the info, I will just make my own tool.

buy a external fuel screw it's the best mod I've ever put on my bike by leaps and bounds it cost about 20 but i can adjust my fuel screw when I'm sitting on the bike. It's the only way to go.

FGR01 said:

I know Tokyomods sells all the leak jet sizes from 35 to 95

I am having trouble with my girlfriends crf250x. It bogs off idle. Heres what I've done:
152 main
45 pilot
stock needle lowered clip 2 positions
stock leak jet
AP block off kit
air box opened up to honda specs
stock air filter
boysen quick shot
baffle taken out of muffler
Zip ty fuel screw 2 3/4 turns out
Pink wire relocated
California 3000 ft
It runs a lot better but it still bogs. Please help.

Unfortunately, it always comes down to educated trial and error. No two people will give you the same advice. This is what I came up with for my 06 250X. It's not perfect but it's close enough for now until something starts to bug me down the road, if it does. I have the airbox opened, stock air filter, PowerNow, Boysen Quick Shot, smog block off, FMF Q2 and the pink wire mod. I ride single track at 0 to 4000 feet and want good clean low and midrange. My bike almost wouldn't run stock it was so lean. I had to warm it up for 10 minutes before it would accept any throttle. Lots of  people like to run theirs rich. I like to run mine as lean as possible with good ridability. I've got a 55 leak jet, 42 pilot, stock needle in the forth position and a 145 main. Now my bike starts with no choke on warm days and 10 seconds worth of choke on cold days. The fuel screw wants to be at 1.5 turns out which tells me it might be a tad rich on the bottom. It now accepts throttle immediately but still needs 5 or so minutes to completely warm up. It's great to not have to sit there for 15 minutes before I can ride. Once warm it pulls cleanly from idle to redline. If I whack the throttle I can almost make it bog but when I ride it correctly it's awesome. I can loft the front wheel anytime I want without fear of it bogging. We'll see if I don't fine tune it down the road but it feels great now.

04 crf 250x. Here’s what I've done:
152 main
45 pilot
stock needle lowered clip 2 positions
55 leak jet
AP block off kit (for smog stuff)
air box opened up to honda specs
stock air filter
boysen quick shot
baffle taken out of muffler
Zip Ty fuel screw set at 2 ¾ turns out
Pink wire relocated (disconnected)
I live in Ca elevation 3000
I know theres more power there somewhere but for now it runs great. It would require expensive mods to get more power such as cam and pipe.

05 crf 250r
northern Ca.  sea level to 3,000 ft. 55 to 85 degrees.
Jd jet kit red needle in 5th position, 175 main, 42 pilot, 55 leak jet. NO BOG!
twin air with no backfire screen.
PMB exhaust cap
Hot Cam

crf250x california model JD kit with airbox mod red needle set at 5 notches from top 158 mainjet 40 low speed air screw out 21/4  turns stock pipe with baffle pulled out. runs great starts great seriously improved torque and revs out nice also. i'm at about 100ft above sea level.

NC elev. 500~3000'

Air box cut
Twin air filter
FMF Q2 exhaust
JD Main Kit
  red needle 5th clip down
  158 main

JD Leak Kit
  50 leak

Stock pilot (40)

Fuel air 2.25 out

Runs great in temperatures 35 deg F to 65 deg F, no bog after moving down to the 50 leak and stock accel, tried the boysen...it didn't help (tested with 65 leak and 55 leak).  Starts a hell of a lot better cold than stock, but seems like i have to use the hot start now after the mods and the bike is hot.

I'm surprised with the amount of power gain, definitely more than expected.




       

I picked up the February issue of Dirt Rider and they have a little "CRF Tips" section which includes suggested jetting for the various models.

For the 250X it suggests

48 Pilot
132 Main
Stock needle

I realize that without knowing what conditions they ride in, this info is of limited use, but it seemed to be a little different take than what I typically seemed recommended either here or at crfsonly for a stock bike.  Seems like they ended up larger on the pilot and smaller on the main.

Anyone have any thoughts?

anyone else have experience with Boysen Quick Shot and Leak jet sizes?  I have read the quickshot is an awsome mod, but can you accomplish the same thing with a differnt leak jet?

Joewith250X said:

Hey Joe, I don't know if you completed the jetting mod yet, but your money and time will be better spent making other adjustments first. I really like the result of the JD kit on my 450 and I presume your result will be very similar. I have spoken to JD about the leak jet mod on my bike and he suggested leaving it alone. I have tuned my carb both with and w/o the exhaust mod and have had no problem getting the bugs out with out changing the  pilot jet, leak jet, air jets, or adding the Boysen cover.

Not to say your bike will not benefit from such mods, but saying you may want to try the needle / main jet combo first.

OK, I did the air box cut, stock pipe and muffler, JD Jet kit.
I ride trails for fun and am going to a few HareScambles this summer.(Ha- A 40 year newbie to Hare Scrambles ) Should I cut the backfire screen out?  I really don't want to drop the $ for aftermarket kit either.  

stock leak jet
42 slow jet  
155 main jet
JD jet kit - red needle 5th position
No Toil Air Filter w/NoToil oil

1,000 ft
30-40 degree f (Right now will be 50-55 in a few weeks, I pray)

I am a little on the rich side right now.
Any "tweeking" recommendations.

Wow, every post is different.  Any recommendations when keeping the stock pipe?  Our Hare Scrambles series requires we meet a db limit.  I had an 05 CRF250R and remember just changing the main and turning out the air screw, it ran great.  What should I do to my stock 06 X ?
thanks

Holy Crap! I put a 150 main in and horsepower increase was unbelievable

i gots a 05 250x
and i puts a 45 pilot in it and a 142 main. just the stock ones outta the 450x.
my needle is at 5. should be at 4 im guessin. the screw is out 1 and  a half. and its idling a bit ruff. thinkin its rich. this is without the snorkle and seems like a bunch more power without the baffle compared to in.  any suggestions?

I could't find a post with my exact scenario, so what are the best settings for me?  I live in NJ which is basically between Sea Level and 1,500 feet (usually less than 500' above Sea Level, but some of the Enduros that I ride in are in the Pennsylvania or Upstate New York hills and have a little bit of elevation), Spring/Summer temps but I ride in the 10s-40s in the Fall/Winter, and I've done NO MODS to my bike at all - even the airbox is totally stock, uncut, stock air-filter and screen.  Can someone who lives and rides in a similar setting with a similar bike setup (i.e., totally stock or close to it) please share which jet setings worked for you?

I just bought the JD Jet Kit, which showed up in the mail today, so here's what I'm thinking:

- JD Jet Kit (just arrived in the mail today!)
- 160 main (too rich?)
- 2nd position clip on the Red needle
- 45 idle
- Stock leak jet? (Should I get the 450's 55 from Honda? - I'd rather not install it and avoide the hassel if it doesn't make a big difference).

42 pilot, 140 main, Boysen quick shot, 2 turns out on fuel screw, and cut open the airbox will make the stock 06 X run great. You wont be able to make the motor hesitate no matter how fast you yank the throttle. That said, adding a hot cam and/or pipe you might want to go up to a 155 or 160 on the main and lift the needle one clip (richer: put clip down one). You certainly can fine tune it closer with different needles and main jets, but I think that will at least put you in the ball park.