535 replies to this topic

[squirrel1 TT Bronze Member]

Model (YZ or WR 250F): 2003 WR250F
Timing (WR-YZ): WR
Main jet: 185
Pilot Jet: 42
Fuel screw (turns out): 2.5 turns out
Needle model/Clip position: JD blue needle 5th position
Airbox lid (on or off): off
Pipe: FMF Q with powerbomb header
Altitude where you ride:1,500-2,500 ft
Temperature where you ride: 40's-80's
Other mods:
Degree of satisfaction:  Very satisfied

[Blaster21996 TT Silver Member]

Blaster21996 said:

It looks like the starting issue has been resolved (see http://www.thumperta...ad.php?t=320903 ) with the help of "Matt96xr6"   . So as of now I still can't confirm my jetting info till next ride.

05 YZ250F
Jetting Confirmed! I rode for 5 hours yesterday at HARDROCK MX in Ocala and the bike ran PERFECT. It also started 1 or 2 kicks evertime, even after a crash.

Current Temp 70d
Elevation: 100ft

Needle: JD Blue
Clip: 3rd
Pilot: 45
MJ: 178
Leak: 45

Other Mods: Boysen QShot
TwinAir Power Up Filter & Cage
PowerNow

Level Of Satisfaction: This is the best the bike has ever run! Virtually no bog.  

[Matt96xr6 TT Titanium Member]

Model (YZ or WR 250F):                  '06 yz250f
Timing (WR-YZ):                            YZ
Main jet:                                      175
Pilot Jet:                                      42
Fuel screw (turns out):                   ~2, little more, little less.  tune to weather
Needle model/Clip position:              JD Red, 4th clip
Airbox lid (on or off): n/a
Pipe:                                           stock
Altitude where you ride:                  0-300 mostly, up to 2000 @ eddysville
Temperature where you ride:           50s currently
Other mods:                                 wiseco 13.2:1 piston, #40 LJ
Degree of satisfaction:                   dialed

[Matt96xr6 TT Titanium Member]

Model (YZ or WR 250F):                '05 yz250F
Timing (WR-YZ): YZ
Main jet: 175
Pilot Jet: 45
Fuel screw (turns out): ~2, little more, little less. tune to weather
Needle model/Clip position: JD blue, 5th clip
Airbox lid (on or off): n/a
Pipe: WB Aluminum Race Pro
Altitude where you ride: 0-300 mostly, up to 2000 @ eddysville
Temperature where you ride: 50s currently
Other mods: #40 LJ

Degree of satisfaction:dialed

[zwr250f TT Titanium Member]

Can we now make this a sticky in the WR forum as well, for the ones who may never venture over here?

[WheelsUp TT Addict]

zwr250f said:

Can we now make this a sticky in the WR forum as well, for the ones who may never venture over here?

    They split the YZ and WR forums?

[zwr250f TT Titanium Member]

WheelsUp said:

   They split the YZ and WR forums?

My thoughts exactly..I voted in the poll and the poll ended in a 50/50 lockup, but I guess they wanted to split it anyway. Hopefully we can all continue to  share the knowledge as we did in the past.

Maybe we should have a forum for wf's or yr's..

[WheelsUp TT Addict]

Ya.... doesn't make a lot of sense.  The primary differences are riding techniques, which are covered by the MX, OR, and DS forums.  

Oh well.

[250Thumpher TT Addict]

Bike: 2001 YZ250F
Cam/Timing Stock timing with 03 decomp cam
Main Jet: Stock 178
Pilot Jet: Stock 42
Needle Clip: Stock 4th
Leak Jet: 40
Pilot Air Jet: Stock 72
Fuel Screw: 1 9/16 turns out
Pipe: White Brothers M-4 exhaust with stock header
Air Filter: No toil w/no toil oil
Engine Work: Wiseco +.25 compression piston, stock plug
Temp: About 60 degrees
Elevation: Bay Area, about 100 above sea level.

Note, this was done with a halfway dirty air filter.

Result: VERY satisfied

Starts up 1 or 2 kicks when cold, first kick when warm with no hot start. Uses hot start when dumped over or right after the engine is stopped. Little soot on exhaust, and a tan spark plug. Probably could use a richer Main jet, but is just fine.

-Philly

[511Dean TT Newbie]

do you think the Power Now was worth the money? what was the benefit?

do you think the JD Blue needle was worth it? What was the benefit?

[HFrettlohr TT Member]

Model (YZ or WR 250F):  '06
Timing (WR-YZ):    YZ
Main jet:   185
Pilot Jet:   42
Fuel screw (turns out):  2 1/4
Needle model/Clip position:  JD blue recommended clip pos.
Airbox lid (on or off): on ...snorkel removed
Pipe:  stock w/ PMB
Altitude where you ride:  1000-3500
Temperature where you ride:  normally 70-90 currently around 50
Other mods:  throttle stop, jd kit, #40 leak jet
Degree of satisfaction: when the temp was up it was much better...loved it. Have some popping right now

[matt113 TT Gold Member]

Model (YZ or WR 250F): 02 wr250f
Timing (WR-YZ): stock wr
Main jet: 185
Pilot Jet: stock
Fuel screw (turns out): 2 1/2
Needle model/Clip position: JD blue needle
Airbox lid (on or off): Lid off
Pipe: stock w/ GYTR quiet insert
Altitude where you ride: 500-1500
Temperature where you ride: moderate (50-60 winter 65-85 summer)
Other mods: all free mods except yz-timing
Degree of satisfaction: very satisfied.. no bog at all. most bang for my buck was the zip-ty fuel screw

[bear09 TT Newbie]

Model (YZ or WR 250F): 2005 wr250f
Timing (WR-YZ): YZ
Main jet: 170
Pilot Jet: 45
Fuel screw (turns out): 1 3/4
Needle model/Clip position: 3rd from top
Airbox lid (on or off): Lid off
Pipe: 450 core through stock shell
Altitude where you ride: 0-500ft
Temperature where you ride: summer 90 - 100, winter 70 - 80 (Sydney, Aus)
Other mods: air box, yz cam, renthal 999's, etc....
Degree of satisfaction: seems to lean off especially when bike gets hot???

Does the leaning off comment seem to make sense???

[yamahaYzDAWSON TT Newbie]

ihave a yz250f and it wont idle do you have any tips

[WheelsUp TT Addict]

Given the information that you provided, the only tip anyone can give you is to do a search and spend the next 5 hours reading everything you can.

It could be:
Misadjusted fuel screw
Clogged pilot circuit
Stuck hot-start
Bad plug
Tight clutch

    

[goneriding TT Member]

Model (YZ or WR 250F): 2006 YZ250F
Timing (WR-YZ): stock
Main jet: 182
Pilot Jet: 45
Fuel screw (turns out): 1.5
Needle model/Clip position: JD Blue 5th down
Airbox lid (on or off): n/a
Pipe: header stock, can = FMF 4.1 ti
Altitude where you ride: 100 ft
Temperature where you ride: 75-90
Other mods: Athena 290 top end, Boysen quick shot, 93 octane pump gas.
Degree of satisfaction: Perfection finally, starts very well, runs clean through the powerband and a light tan plug!  This is first bike I have purchased in my 30 year mx experience that was jetted so lean from the factory.  I think the key was richening up the pilot and the main, changing from a stock needle four clips down to a JD five clips down did not seem to change much.  BTW the Athena mod did not seem to alter the jetting very much (it was lean stock and was just as lean after the big bore kit).  Also wanted to mention that I acheived a satisfactory plug reading before I added the quick shot but had to go to a 48 pilot to do so, in other words the quick shot seems to richen up the pilot circuit by about one size.

[DirtRacer TT Newbie]

I too have a 2001 WR250F.  I was wondering what type of exhaust system you are using on your bike?  I still have the stock exhuast system.

Thanks, Ken

[Poolboy TT Newbie]

Model (YZ or WR 250F): 2003 WR
Timing (WR-YZ): WR
Main jet: 185
Pilot Jet: Stock
Fuel screw (turns out): 2
Needle model/Clip position: JD blue/ #4
Airbox lid (on or off): Off
Pipe: Yosh
Altitude where you ride: 0-5000 ft
Temperature where you ride: Around 65 right now
Other mods: All the free mods w/ Power Now, Twin-Air Filter w/o Backfire Screen, #40 Leak Jet, Air box cut open.
Degree of satisfaction: Who needs a 450?!?  

[mechyank TT Member]

Model (YZ or WR 250F): 2004 WR 250F
Timing (WR-YZ): YZ
Main jet: 185
Pilot Jet: 40 (soldered and drilled in a pinch)
Fuel screw (turns out): 1.5
Needle model/Clip position: JD Blue 5 from top
Airbox lid (on or off): Off. I also cut the top and replaced the stock battery.
Pipe: Titanium 4 with powerbomb (Ebay $30, yes 30.)
Altitude where you ride: 500 - 1500ft
Temperature where you ride: 50 - 95f
Other mods: all free mods, flatland radiator guards, skidplate, hot cams, neoprene "seal savers", powernow, oh yeah I forgot, HOT CAMS!
Degree of satisfaction: I rode VetC NY WNYOA in 2005 and got 8th of 25 my first year racing.  I just did some mods for this year...  I went from stock pipe with a aftermarket insert to the powernow plus the cams and fmf pipe with powerbomb all at once.  What a difference!  I am very hopeful for this season.  This bike cranks now!!!   

[kenshinrider TT Member]

Model (YZ or WR 250F):WR250F 06
Timing (WR-YZ):WR
Main jet:180
Pilot Jet:40
Fuel screw (turns out):1.5
Needle model/Clip position:OBELQ Clip at #4
Airbox lid (on or off):Snorkel out with holes cut in side
Pipe:E2 with powerbomb SX
Altitude where you ride:500-1500 ft
Temperature where you ride:currently 50-85f
Other mods:All free mods, Twin air filter w/o screen,flatlands skidplate
Degree of satisfaction: Runs great...big improvement over stock.