Page 1 of 3 123 LastLast
Results 1 to 10 of 21

Thread: another Ex to YZ conversion

  1. #1
    Join Date
    Nov 2005
    Location
    Charlotte_NC
    Posts
    522

    another Ex to YZ conversion

    so im going to convert my 400ex to a yz426. I need to know whats all is involved. I have done alot of reading and have a pretty good idea.

    FRAME- NO Modification other than Radiator mounts

    Oil tank - going to have a custom sheetmetal one built

    Radiator - Stock 250R radiator w/ engine ice? Will that cool enough for trail riding, or should i go oversiezd? If so What size, kind?

    Motor Mounts - buy a kit from ss440ex

    kicker - ???? Ive heard of extensions and what not but open to suggestions here.

    Throttle - YFZ cable

    clutch cable - ???? Do i use the stock yz cable w/ my RTC levers??

    Exhaust - Going to buy a HMF/ Yoshi 400 slip on and build custom mid pipe

    Rear suspension - i dont have to change to a no link do i?? I can use stock 400 rear

    Am i headed in the right direction.

    Also open to suggestions about Colors,

    heres what im thinking, White/Gray, Laker Customs, Black frame/swingarm/ Lower a-arms. Chrome subframe/ stem/ Upper a arms

    Silver/gray Spindles

    Black rims
    07 700 Raptor SE
    Alba Racing Power Kit
    15t sprocket

    02 400ex - Turtle Racing 440 Stroker Engine (416 Bore, +4mm Stroke), JE 14.5:1 piston, Sparks Racing FCR 39mm carb, Hinson 8 plate clutch, Full Port and Polish, Curtis Sparks x4 cam, Curtis Sparks X-6 exhaust, UM aluminum airbox, ASR +2+1 A-arms, +4 Lonsetar Axle, Houser +1 antivibe, Works Triple rates with Remote Rezzies, Custom blue powdercoat, Maier Gray Plastics, theres nothing like the smell burning 110 octane...PARTING OUT! ASK ME FOR PARTS

    Ask me about THE QUAD SHOP

  2. #2
    Guest
    Frame has to be moded no matter what. Needs mounts and the stock mounts need to be cut off.

    Yz motors run hotter than the air cooled ex motor. Mine boils over around 20 minuts during the summer and i runa 250r pwr radiator. The pwr is not much bigger than stock. Nacs looks double the size of the pwr.

    ss440ex only has a couple mounts left cause he is not making them no more.

    you use the yz clutch cable and it hooks up to stock clutch lever fine.

    rear link is fine


    to extend the kicker yo ueither buy a extention or make your own. To make your own you buy a extra yamaha nuckle and then put a 1" piece of aluminum tubing between the two.


    For me to have every thing modded so i could just put the motor in and go costed me only $270. I just found a guy that welds for a living and he welded it and made the front motor mounts out of aluminum.

  3. #3
    Join Date
    Apr 2003
    Location
    Minnesota
    Posts
    147
    Basically the only costs in doing my yz 426 swap were the cost of the engine/exhaust/electronics/ and a new radiator. If you have access to some metal scraps from a welding shop, a welder, and a little bit of ingenuity you can do it no problem. I went about the swap in a little more of a non-traditional way. I chopped the diagonal frame rail in front of the engine and put in 2 vertical frame rails to make it look somewhat like a v when viewed from the side. (I'll get pics to show you what I mean) I then made radiator mounts in between those 2 rails, and made oil tank mounts on the engine side of the back rail, and was able to utilize the stock 400ex oil tank. You will have to set everything in and mock it up exactly how it has to be, then line the sprockets up, weld a crossmember on the bottom side of the frame for the bottom engine mount, and then cut ears for that and mock them up and tack them in place. You will have to make some special bushings for the swingarm to space the engine over correctly. For the kickstarter, the guy above me is correct..go to your yamaha dealer, buy another knuckle (about 30 bucks) and then place a piece of pipe in between the two to space it out, and then smoke it into place. (Make sure it's straight!!) Then there is still the head stay and lining up the intake. There are a few different ways to do this...I'm in school right now and kind of pulling stuff off the top of my head so if you really need some help and advice send me a pm..I've converted two 400ex frames for yz engines with great success.. Also, make sure you gusset the frame in every area possible..those yz engines have a motherload of torque and like to break ****..
    2007 JRD/Elka/Sparks/HiPer Honda 450R

    Contact me for any custom welding/fabrication needs

  4. #4
    Join Date
    Jul 2005
    Location
    NC
    Posts
    1,352
    i would deff get a aftermarket rad.
    Judgment comes from experience, experience comes from poor judgment.

    05' YFZ450-Elka, Fasst, W.E.R., Curtis Sparks, Pro Armor, Champion, ASV, Pro Design, QuadTech, AC, PRM, maxxis/ITP, oury, powermadd

    YZ 250- pro circuit, total control, weisco, oury, renthal

    KX 500--to much to list

  5. #5
    Guest
    Originally posted by oldskoolex400
    i would deff get a aftermarket rad.
    It s going to need a duzzen rads just to keep it cool.

  6. #6
    Join Date
    Nov 2005
    Location
    Charlotte_NC
    Posts
    522
    BuiltBlaster88 check your PM's
    07 700 Raptor SE
    Alba Racing Power Kit
    15t sprocket

    02 400ex - Turtle Racing 440 Stroker Engine (416 Bore, +4mm Stroke), JE 14.5:1 piston, Sparks Racing FCR 39mm carb, Hinson 8 plate clutch, Full Port and Polish, Curtis Sparks x4 cam, Curtis Sparks X-6 exhaust, UM aluminum airbox, ASR +2+1 A-arms, +4 Lonsetar Axle, Houser +1 antivibe, Works Triple rates with Remote Rezzies, Custom blue powdercoat, Maier Gray Plastics, theres nothing like the smell burning 110 octane...PARTING OUT! ASK ME FOR PARTS

    Ask me about THE QUAD SHOP

  7. #7
    Join Date
    Dec 2003
    Location
    Texas
    Posts
    1,661
    Oil tank-yes you will need one or do the wet sump system.
    I sold my last one a week ago.

    Kicker- buy a $32.00 yz knuckle machine off the post and weld a 1 inch piece of tube between the two.

    Throttle cable- use the yfz 450 quad cable.

    Clutch cable- the one off the yz bike will work great.

    Exhaust- Use the yz header pipe and which ever silencer off a 400ex, have a 6 inch mid pipe made. I like the Thunder Alley header pipe. works great and looks super high tech!!

    E-mail me for any help with pics!!
    Thanks again,
    Al
    Attached Images Attached Images
    LMS Racing....
    Metal fab & welding

    Thanks to JH-Racing

  8. #8
    Join Date
    Nov 2005
    Location
    Charlotte_NC
    Posts
    522

    one more one

    is there a difference in teh mounting of a yz450 and a yz426?

    ss440
    You dont sell those extension do you, thats just a pic of what i need to make?
    07 700 Raptor SE
    Alba Racing Power Kit
    15t sprocket

    02 400ex - Turtle Racing 440 Stroker Engine (416 Bore, +4mm Stroke), JE 14.5:1 piston, Sparks Racing FCR 39mm carb, Hinson 8 plate clutch, Full Port and Polish, Curtis Sparks x4 cam, Curtis Sparks X-6 exhaust, UM aluminum airbox, ASR +2+1 A-arms, +4 Lonsetar Axle, Houser +1 antivibe, Works Triple rates with Remote Rezzies, Custom blue powdercoat, Maier Gray Plastics, theres nothing like the smell burning 110 octane...PARTING OUT! ASK ME FOR PARTS

    Ask me about THE QUAD SHOP

  9. #9
    Join Date
    Dec 2003
    Location
    Texas
    Posts
    1,661
    Yes I can do a extension for you...

    The lower mounting bolt hole on the 450 is located maybe .200 towards the rear of the engine then the yz426.

    Kits will work either engine.

    pm me on the kicker extension..
    Al
    LMS Racing....
    Metal fab & welding

    Thanks to JH-Racing

  10. #10
    Join Date
    Nov 2005
    Location
    Charlotte_NC
    Posts
    522

    tranny problems

    Has anyone had any issues with tranny failure, ive heard that the trannies from dirt bikes take a real beatin when you put them in quads due to teh extra traction and weight that they are havign to haul!
    07 700 Raptor SE
    Alba Racing Power Kit
    15t sprocket

    02 400ex - Turtle Racing 440 Stroker Engine (416 Bore, +4mm Stroke), JE 14.5:1 piston, Sparks Racing FCR 39mm carb, Hinson 8 plate clutch, Full Port and Polish, Curtis Sparks x4 cam, Curtis Sparks X-6 exhaust, UM aluminum airbox, ASR +2+1 A-arms, +4 Lonsetar Axle, Houser +1 antivibe, Works Triple rates with Remote Rezzies, Custom blue powdercoat, Maier Gray Plastics, theres nothing like the smell burning 110 octane...PARTING OUT! ASK ME FOR PARTS

    Ask me about THE QUAD SHOP

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
  •