Page 1 of 3 123 LastLast
Results 1 to 10 of 22

Thread: 400ex extensive upgrades

  1. #1
    Join Date
    May 2007
    Location
    Maryland
    Posts
    109

    400ex extensive upgrades

    Here’s my list of mods that I am going to put on my 2007 400ex let me know what you think and any suggestions.

    Suspension – Elka triple rate sport & racing front shocks w/ piggyback reserviors
    Elka dual rate sport & racing rear shock w/ remote reservoir

    Engine – Head Port and polished
    Hot Cams stage 2 cam
    Titanium valve springs
    Hardfaced rockers
    Ice cube/max power 440 bore cylinder
    Hot Rods stroker crankshaft and double forged rod (460cc)
    K&N replacement filter
    K&N Xtreme power lid
    Procircuit T-4 slip-on
    Stock head pipe for throttle response
    Extensive carb tuning
    FST secondary oil cooler
    Heavy duty clutch springs
    2004 450r
    2007 400EX

    "Run her hard, but at the end of the day treat her like a lady!"

    "Fix it right or fix it again"

  2. #2
    Join Date
    Apr 2005
    Location
    Phoenix, AZ
    Posts
    962
    Not a bad plan by any means. The only thing I would change would be the Pro Circuit exhaust ... it's not the best choice. For what you are doing, look into a Sparks or even a HMF.

    My question is why go immediately to the 460 stroker kit? For the most part, 400EX owners will progress through bores as needed, going from a 400 to 416 to 426 to 440 and then maybe a 460.

    As for the Elka's, be sure to be very honest with whoever is taking the build specs for them. Your weight, tire size, riding style, etc. plays a huge role in the setup. Elka doesn't seem to have the best valving from the factory as it is so make sure to provide correct info so it will at least be close.
    Sponsored by Dirt Fiend Racing (DFR) of Mesa, AZ ~

    2004 Honda TRX400EX (RED)

    PEP, Hydrodynamics, Lonestar Racing, Rath Racing, Pro Armor, Pro Taper, ASV, Streamline

    2009 KTM 450SX ATV (ORANGE)

    Fox Racing Shox, Lonestar Racing, Precision, Houser, Motoworks, Hiper, Fuel Customs

  3. #3
    Join Date
    May 2007
    Location
    Maryland
    Posts
    109
    i'll look into the exhaust. one of the reasons i picked the exhaust because on my friends bike it helped with throttle response. also i really like the deep throaty sound that it produces. as for the 460 kit I do alot of trail and mountain riding and i prefer alot of torque and low end to mid range power which is nice in the conditions i ride.
    2004 450r
    2007 400EX

    "Run her hard, but at the end of the day treat her like a lady!"

    "Fix it right or fix it again"

  4. #4
    Guest
    Originally posted by chayes627
    i'll look into the exhaust. one of the reasons i picked the exhaust because on my friends bike it helped with throttle response. also i really like the deep throaty sound that it produces. as for the 460 kit I do alot of trail and mountain riding and i prefer alot of torque and low end to mid range power which is nice in the conditions i ride.
    get a HMF or Sparks and it wil maximize yoiur gains with those mods. I also disagree on the shocks, i think there are way better and even cheaper alternatives to Elka. The K&N power lid isnt worth it either IMO, it will restrict flow over a open air box lid and will set you back $100. If you want the protection of no air box lid with all the same flow get a Outerwears air box cover $19. And with the hardfaced stuff I think thats only for WebCams not Hotcam. With hardfaced stuff I think it will eat up your hot cam.

  5. #5
    Join Date
    Jan 2008
    Location
    princefredrick,md
    Posts
    865
    The money you spend doing that to that 400ex you could get a 450 .

  6. #6
    Join Date
    Sep 2005
    Location
    Suring Wisconsin
    Posts
    5,448
    Gonna be pretty hard to move a quad without A-arms, what have you decided on them? Whats your budget?
    ~Dallas~

    03' Roll Design/IMS-Roll/Custom Axis/C&D Racing 416ex

    Special thanks to...
    Colby@C&D Racing
    Hardkor Engineering
    G4 Graphics
    Team2powersports
    RockyMountain ATV
    Chino886
    K&K ATV
    JL ATV
    Magic Racing
    Blais Racing
    Metro Powersports
    IMS/Roll Design
    Motosportoutlet
    Badger Cycle
    And To my wife

    Motor mods- JE 11:1 comp,Stg 2 Hotcam,C&D Race ported head,Stock carb jetted,White Bros pipe. Ran on Turbo Blue 110

  7. #7
    Join Date
    Apr 2004
    Location
    KS
    Posts
    2,295
    FoxHondaRider tell me your experience with elka and with other shocks? Elka makes a good shock and has good customer service. Their valving might be alittle bad at times. But most people who say that are not able to setup their suspension correctly, so they blame someone else.
    Do not get the hardened rockers with a hot cam, it will eat you cam. You will need a hardwelded cam to accompany those rockers.
    As for exhaust I would look into a Sparks x-6 or HMF full system. They will maximize your hp.
    You should also get HD head studs, GT Thunder.
    Hope this helps.
    Mitch
    2003 Jb crf450

  8. #8
    Join Date
    May 2007
    Location
    Maryland
    Posts
    109
    the reason im not going with wider a-arms and axle because i mostly do trail riding and dont want to ahve any problems with that. so i figure if i get the thing lowered down with the elka's ill be able to get to stick better
    2004 450r
    2007 400EX

    "Run her hard, but at the end of the day treat her like a lady!"

    "Fix it right or fix it again"

  9. #9
    Join Date
    Nov 2005
    Location
    Chandler, AZ
    Posts
    4,021
    Why titanium valve springs? Did you mean titanium valve spring retainers?

    Why the hardfaced rockers? As mentioned, make sure the rockers and the cam are the same "hardness".

    There is no Ice Cube cylinder for the 400EX. I'm sure Max Power will be happy to re-sleeve you stock cylinder though.

    All that and no carb upgrade?

    What piston?
    "It ain't what you don't know that gets you into trouble.
    It's what you know for sure that just ain't so. "

    --Mark Twain

  10. #10
    Join Date
    Apr 2004
    Location
    KS
    Posts
    2,295
    maxpower does make a cylinder, their website still sells one.
    Mitch
    2003 Jb crf450

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •