194 replies to this topic

[CaptainStupid22 TT Newbie]

I have a 2005 CRF250R. WhiteBrothers Pro I. Boyesen AP. 155 main jet. Needle on 6 slot. Air screw is 2 turns out. Bike feels flat. Feels good mid and high but low is a little rough. any suggestions. Also thinkin about going to a 110 in the back. Good or Bad?

[sly69 TT Silver Member]

hey h-rider, its none other than the sly man here ,

[TT_CRF250X TT Newbie]

I couldn't take it anymore...the off-idle bog of my 250X was maddening.  After reading wheelsoff's post I figured "what the heck".  I went with the some of the same carb mods: 130 to 150 main jet, 40 to 45 slow jet, and dropped the needle clip 2 slots. Didn't mess with the leak jet.  But anyway, talk about a huge difference!!  It's like riding a completely different bike!  Crack the throttle and BAM, the power is there!

[motoxer614 TT Member]

what setting should i put on a stock crf250 with a boyesen quickshot accelarator pump

[motoxer614 TT Member]

can somone reply quikley thanks

[Hondaracing915g TT Gold Member]

What's the best jet kit, that won't ruin the engine?

[KDXfile TT Bronze Member]

'05 250X with a FMF Powerbomb header and Q muffler.
160 main, 45 pilot, stock needle at #4, FS 2 turns.
Riding at 500' ASL, temps 80-100.

The bike runs great with no bog.

[CRF230Rider TT Newbie]

I just finished re-jetting my 250X today. Huge gains in power and throttle response. No bog either! Changes were as follows: 150 main, 42 pilot, stock 55 leak jet, lowered needle clip two positions form stock. Fuel adj. screw is two turns out. Airbox is slightly opened up on top to a 3" x 3+1/2" opening(not near as much as the CCC mod) and the baffle has the Rick Ramsey modification done to it. Elevation here is 900 ft. and the temps in the low 90s. Best $14 I've ever spent.

[ULEWZ TT Platinum Member]

CRF230Rider said:

I just finished re-jetting my 250X today. Huge gains in power and throttle response. No bog either! Changes were as follows: 150 main, 42 pilot, stock 55 leak jet, lowered needle clip two positions form stock. Fuel adj. screw is two turns out. Airbox is slightly opened up on top to a 3" x 3+1/2" opening(not near as much as the CCC mod) and the baffle has the Rick Ramsey modification done to it. Elevation here is 900 ft. and the temps in the low 90s. Best $14 I've ever spent.

This is exactly what I did (except the Ramsey mod as I don't know what he did) and the bike runs flawless. Starts right up after putting on a Kouba T-handle pilot screw and adjusting to 2 turns out.

[CMB#23 TT Gold Member]

Does anyone know what kind of jetting I would need for my Pro Circuit Ti-4 SL at 0-1000 ft altitude?

[witkop TT Member]

Who can help me out.... what jetting would you lot recomend for my CRF250R in the UK, probably a little over sea level if any at all.
I have heard so many different options. Got stock pipe and will remove screen from air filter.   

[Quasimoto TT Member]

NE corner USA
06 CRX 250 X

Airbox Mod 4.5x4
Leak Jet: 70
Pilot: 42
Main jet: 160
JD Kit, red needle, 5th clip from top
Koobalink extended fuel screw: 2 turns out
PowerNow intake

The machine runs very strong and no bogging

Phil

[Old Fart TT Newbie]

Sea Level 250-04' X.  135 Main, 142 P, Needle stk. 2 notch from top of needle.
100 mile dual sport, 45 mpg. plug perfect tan, don't use the hot starter lever, never missed a beat. Drop, pick up and start right now.  Crisp and no hesitation anywhere through the range.

[i heart ridin TT Gold Member]

..............

[skipn8r Get Help Now]

I suppose I ought to post my jetting as it seems to be working well.  Thanks to Ramsey for all the reference materials .

'05 49-state 250X
Full CCC mods
5,300 ft elevation riding
40 - 100 degree temps

Slow Jet: 42
Needle: NCYS (CCC needle), 2nd clip (I might drop to 3rd when cold)
Main Jet: 145 when hot outside, 148 when cold
Fuel screw: 1-1/2 - 2 turns out, whatever runs best
Leak jet: 70

[buzzardrider TT Newbie]

I have a 160 main and the stock crf250r silencer. good? bad? carb changes? I'm gonna take off the airbox snorkel too.

[azulick TT Newbie]

Hi. Are you still reading messages from here?
DV8X

[secretsqrl TT Newbie]

158 main jet
42 pilot jet
ncys-4 pos. needle
2 turns air screw
pro circuit exhaust

[secretsqrl TT Newbie]

get a hold of doc wobbs, he can help you.

[shouldabeen TT Bronze Member]

Clarksville, Ar   250x W/r Pipe&header, Air Box Cut, No Tiol Airfilter
400ft To 1000
Main Jet130 Stock To A 170
Pilot  40 Stock To A 42
Leak Jet 55 Stock
Needle Clip Down To The Four Slot 2 More Than Stock
A/c Pump Adjustment Screw One Full Turn
Fuel Screw Or Pilot Adjustment 2 1/4 Turn
No Bogg Great Power