Jetting help!
  • Kprato32
    Posts: 3
    Joined: Mon Apr 22, 2019 5:49 pm

    Jetting help!

    by Kprato32 » Mon Apr 22, 2019 6:06 pm

    So I can’t get the jetting right on my bike for the life of me.......

    Model:2005 crf450x
    Air box: cut on top and side
    Back fire screen: gone
    2006 crf450r head
    2002 crf450r CAM
    FMF power up needle (clip ring set per instructions for 0-3000 feet)
    Current jets 52pilot and 152 main
    FMF power bomb header and power core 4 exhaust
    O-ring accelerator pump mod

    The bike starts and isles but stalls when I hit the gas. Sometimes I can take off and it’s fine once I’m on the gas and moving....... whacking the throttle causes bog or stalling! Any advice!?!? My mind tells me a leaner pilot but I’m lost at this point.
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Jetting help!

    by JimDirt » Mon Apr 22, 2019 10:21 pm

    Welcome to the site !! \:D/

    You are waaaaay too rich on the pilot , you need to be about 45 , and kind of lean on the Main , also , part of the bog can be the AP timing , when you did the mod , did you make sure that the squirt just misses the slide and goes right into the venturi ?? , also a AP Pump cover will help as well

    https://www.crfsonly.com/catalog/produc ... ts_id/2310

    This is a Jetting guide to go by

    Jetting Guide for Main Jet:(pilot 45) CRF450R/X

    Sea level....165
    2000 ft.......162
    4000 ft.......160
    6000 ft.......158
    8000 ft.......155


    Temperature/Elevation:
    One main jet size (up/down) for every 2,000 feet or 25 degrees in temp.


    I am at 2000 ft and ride to 8000 with my 06 450X , I have 45/162 , 65 Leak Jet , fuel screw 1-1/2 _ 1-3/4 , Quick Shot (QS1 not QS2 , as they did not have the 2 when I got mine), needle 4th clip (NCVS needle) , O-Ring Mod , Pink Wire Mod *on KTM Map Switch , so I can change from stock/smooth power delivery for tight stuff to snappy for more open/fast riding, on the fly* , top of airbox cut *as per Competition Mod*, and a 05 450R muffler with a PMB endcap , HotCams Stage 1 , I maybe adjust the fuel screw that 1/4 turn for those elevation changes ... no bog or hesitation ever ....

    Hope that helps some ;)
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Kprato32
    Posts: 3
    Joined: Mon Apr 22, 2019 5:49 pm

    Re: Jetting help!

    by Kprato32 » Tue Apr 23, 2019 11:58 am

    Thanks for the feedback! Yeah when I did the AP mod I made sure it cleared the slide.

    I’ll definitely start by leaning out my pilot jet!

    Also my bike never used to backfire when I’d let off the gas until I installed the new head. I’ll definitely richen up the main as well.

    Thanks again, I’ll let you know how it goes soon!
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Jetting help!

    by JimDirt » Tue Apr 23, 2019 6:52 pm

    Thanks for the feedback! Yeah when I did the AP mod I made sure it cleared the slide.

    I’ll definitely start by leaning out my pilot jet!

    Also my bike never used to backfire when I’d let off the gas until I installed the new head. I’ll definitely richen up the main as well.

    Thanks again, I’ll let you know how it goes soon!

    No problem , glad to help ;) ...... keep us posted ..... 8-[
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Kprato32
    Posts: 3
    Joined: Mon Apr 22, 2019 5:49 pm

    Re: Jetting help!

    by Kprato32 » Sat Apr 27, 2019 3:38 pm

    So it turns out that was my old jetting set up when I bought the bike. I had already changed them to a 45 pilot and a 162 main. I messed with the fuel screw by tightening it and then backing it out a turn and a half. Bike ran amazing no bog no back fire!

    I went to adjust the idle right after and noticed the fuel screw spinning from the vibrations.

    Turns out that’s been the issue all along so I bought a new one! I did also order the quick shot too so I’m curious to see if that helps even more!
  • User avatar
    JimDirt
    Posts: 4406
    Joined: Sat Nov 25, 2006 6:31 pm

    Re: Jetting help!

    by JimDirt » Sat Apr 27, 2019 6:21 pm

    Thanks for the update .... make sure you have the old O-Ring removed and that the seat is clear , as the screw should not move at all as it is under spring tension , so something was missing , broken , or not installed correctly for it to do that

    When installing the new one , make sure its Spring ,Washer, O-Ring , O-Ring being at the end , going in first in the opening , snug it down to just lightly seated (do not force or crank it down) , then back it out and you should be good ....
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho

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