CRF's Only Forums

Jetting database for Honda CRF's

Please post with:

Model: 450X or 450R or 250X or 250R
Settings for what altitude: nnnnn ft
Main jet size:
Needle used: Stock or otherwise
clip location: 2nd, 3rd, etc.
Airbox mods: cut open, stock, etc.
Air Filter changes:
Any other related changes:

If you ride at different altitudes, make an entry for each...

Thanks! Jim CRF450X 2005

speedilad...welcome to the group. so why the range of requests for jetting information? looks like you have a 450X?

i think speedilad has a good point. it would be great if everyone would have in their signature their jetting and needle settings along with altitude and location. this would be a big help to others. me personally, i doubt i'll do anything other than have jd jetting kits installing in all of our crfs. they work that well and eliminate the day or so of jetting and testing.

ken

speedilad wrote:Jetting data base for crf's

I'm in.

Model: 05 450X

Altitude: 450MSL
Main jet size: 160
Pilot Jet: 42
Needle used: 16233-MEN671
(I think the stock needle would work just fine but in 4th clip)
Needle clip location: 3rd Clip
Airscrew: 1 1/8 turn

Airbox mods: Top of box cut away. No holes in outside
Air Filter changes: Stock filter

Other related changes:

Headlight on/off switch
Race Sag: 3.5 inches
Forks: Raised 1.5cm

Rekluse Z-Start Auto Clutch w/ Perch Adjuster
Flatland SkidPlate
Pro-Taper Fatbars
Scott's Steering Damper
BRP Bar mounts
Acerbis Multiplo BarkBuster
Fastway Case Saver
Works Connection Shark Fin
Works Connection Rear Master Cylinder Cover
Unabiker Radiator Guards (www.unabiker.com)
RBR Wheel Spacer/Seal Savers
Progrips - Safety wired
Custom License Plate bracket
Dunlop 756s Front and Rear
Pink Wire Mod
Lynx Computer w/ Remote Switch
Fastway Wheel Spacer
Stock Exhaust w/Baffle removed

Mobil V-Twin 20/50w Synthetic

Yes I do have a 2005 CRF450X - first rides this week - awesome. Home ride is in Eastern Penna. Annual trips to Colorado and Utah. Looking to help others that are new to 450X and maybe save myself and others time. The XR400R riders had an excellant data base with about 25-30 entries from riders all over the map...

I am planning on creating a pdf file report of the results and post it here when done.... Not many takers so far...

speedilad wrote:Yes I do have a 2005 CRF450X - first rides this week - awesome. Home ride is in Eastern Penna. Annual trips to Colorado and Utah. Looking to help others that are new to 450X and maybe save myself and others time. The XR400R riders had an excellant data base with about 25-30 entries from riders all over the map...

I am planning on creating a pdf file report of the results and post it here when done.... Not many takers so far...

speedilad,

Might post a notice out in the general forum to let everyone know to come here and fill it out.

Rob,

I looked. Where is the best place to post as you suggest? I don't see a general topic.. Thanks!

Jim

I'd put a post in each of the targeted categories, ie., 450R, 450X forums.

05 CRF 450X 700 ft. ASL.

JD kit per directions -Red needle in 4th clip, 45 pilot, 1 and 3/4 out on the fuel screw,162 main jet

HotCams Stage 2 camshaft

Crfsonly fuel screw

Twin Air Powerflow

Air Box sides/top open

FMF PowerBomb header with Yoshimura slip-on.

Pink Wire Mod.

Applied Triple Clamps
Rekluse with perch adjuster
Scotts steering dampener
AceWell 3700 speedo/computer
Cycra ProBends hand guards
Applied crankcase vent kit
TyDavis axle blocks
Hammerhead shift tip (For size 14's !)
Pingel oil filler cap
Bitchin' red valve stem covers
Unabiker radiator guards
Race Tech re-spring/re-valve front and rear
TM DesignWorks buffer/guide/rollers
Works Connection Elite clutch perch
IMS footpegs
IMS 3.2 fuel tank
Project 321 gas cap

crf450x 2500'-9500' tested
'05 R Cam
12.5:1 JE Piston
36mm TRX Intake Valves
JD Red Needle 4th pos.
170 Main
45 Pilot
XR's ONLY Fuel Screw @2.25 avg.
BOYESEN APC {a must}{no adjustments to linkage}
O-Ring Mod to linkage
PINK Wire Mod
AIRBOX Mod per Honda Wrench {emulates R box}
TWINAIR Air Filter {backfire screen removed}
TWOBRO CAN


paul #1

JD kit
Red needle 4th clip position
170 main
45 pilot
Twin Air Powerflow
Opened airbox (Completely Hacked)
Boyesen APC
XR's Only Fuel Screw. 1-1/2 out TBD
"R" Can with PMB end cap

158 Main
45 Pilot

I live at 1180 ft above sea level. Really woke the bike up and stopped the pinging.

First off, JD gets it REALLY REALLY CLOSE! But, I spent DAYS perfecting this!

Altitude: 300ft

JD jet kit

172 Main jet (not in kit, but needed)

Red needle on 5th from top (tried 4th from top as recommended but just to lean mid throttle. between 4 and 5 would really be ideal!)

Screw is 1.5 turns out (1.75 and the bike will stall with a quick tap of the throttle. same for 1.25)

All mods are listed in below. Throttle is response better than many two strokes!!!

Oh yeah, It didnt have any change on jetting at all, but I changed to 110 octane, leaded, Torqo race fuel. Not much power increase if any, but WAY smoother running.

05 450x 800 ft elevation

White Bros smog eliminator kit
Applied crank case re-routing kit
Twin Air power flow kit
Stock exhaust baffle removed
Air box mod per Honda Closed Course racing only doc Includes side airbox hole cut.
JD jet kit - 170 main and red needle jet with clip in middle.
CRFSonly fuel screw, set to 1 1/8 turns
Napalm racing air filter screw.

Just finished tonight, it took a while to start but maybe because of lack of fuel. Cold to start but once warm it rails like no other.

I might try tomorrow to reset the fuel screw in conjunction with the idle screw, I feel it may not be out enough.

Virge, with the top AND sides cut, especially like Honda has you do it, you're gettin a little more air than we are. Try 1 and 1/4 out on the fuel screw, that may fix the cold to start thing. Let me know how that goes. Doug