1. Thanks for visiting The Forums at DirtRider.Net. Please join us and gain access to advanced search functions and other features that will make the most of your time here.[ Do it! ]

2002 Honda CR 125 Big Bore

Discussion in 'Dirt Bike Mods & Maintenance' started by hoov165x, Jun 1, 2002.

  1. hoov165x

    hoov165x Rookie
    Member

    Joined:
    May 31, 2002
    Messages:
    106
    Likes Received:
    0
    My version of the ultimate vet bike would be a KTM 200 motor in a CR 125 Frame. This will probably not be possible anytime soon, so I need advice on the useability of big bore kits. Wondering if anyone out there can tell me if the CR 144's have anywhere near the bottom end power of a KTM 200 while maintaining the stock high RPM power. As you can see I am a lazy 250 rider that wants to have his cake and eat it too!


     
  2. marcusgunby

    marcusgunby Lifetime Sponsor

    Joined:
    Jan 9, 2000
    Messages:
    6,450
    Likes Received:
    0
    The post 2000 Cr125s can only go to 133 as the powervalves dont allow 144cc.The 133 runs well but aint no 200.
     
  3. Jman271

    Jman271 Subscriber

    Joined:
    Oct 18, 2001
    Messages:
    317
    Likes Received:
    0
    In the back of the dirt bike mag ad's everybody and their brother has kits avavilable for CR's. I don't know for first hand exp, but from what I have heard the Eric Gorr 133 w/ port job, w/ pipe/silencer is hard to beat.
     
  4. robj

    robj Rookie
    Member

    Joined:
    Oct 31, 2000
    Messages:
    71
    Likes Received:
    0
    On the quest of the ultimate woods bike: can the 2002 CR cylinder/power valves be modified to expand the capacity to 150cc plus? I thought I heard about 167 conversions. Would you need a different ignition pattern to create a linear power delivery? Also are there compatible Honda gears to create a longer 5th? How about flywheel weights and lighting? Thanks for any info...
     
  5. imlostagain

    imlostagain Rookie
    Member

    Joined:
    Feb 12, 2002
    Messages:
    91
    Likes Received:
    0
    I believe the 167 is a stroker motor costling upwards of $1800. I too read the cylinders can only go to a 133 bore. I have a '99 CR144 and am very pleased with the power compared stock. The motor has considerably more low-end and brings on the power more similar to a 250 than a 125. Unfortunately , I haven't compared my bike to a KTM 200 but I wouldn't hesitate to go the overbore route especially considering Eric Gorr has VERY reasonable rates on his work . Hope this helps ...
     
  6. marcusgunby

    marcusgunby Lifetime Sponsor

    Joined:
    Jan 9, 2000
    Messages:
    6,450
    Likes Received:
    0
    If you really want a 144 you need to get a 99 top end complete with actuator arm for the powervalve and you will need to be able to fabricate the exhaust manifold.I wouldnt go for a stroker 125 as they make weird power from the dyno charts ive seen.
     
  7. DEANSFASTWAY

    DEANSFASTWAY Lifetime Sponsor

    Joined:
    May 16, 2002
    Messages:
    1,192
    Likes Received:
    0
    Ive made them 154 but you have to weld up the cylinder and plug up the exhaust ports . There in some micro sprints out here , they kill the new RS motor . Were using a dome piston but are working on the flattop setup. Theyrip.
     
  8. MX Madman

    MX Madman Rookie
    Member

    Joined:
    Oct 7, 2000
    Messages:
    31
    Likes Received:
    0
    My son races a 98 E.Gorr 144,with the "Mo Better Everywhere"porting and a 250 airboot.....This thing rips for a 125.Great bottom,and more mid than I thought you could get from a moter this size.And the topend rev`s great. :cool: I currently race a 96 cr250,but would be very happy racing this bike.I have been thinking racing it in the Vet+30 to see how it would do. :D
     
    #8 MX Madman, Jun 19, 2002
    Last edited: Jun 19, 2002
  9. NO HAND

    NO HAND Subscriber

    Joined:
    Jun 21, 2000
    Messages:
    1,198
    Likes Received:
    0
    I agree with that too. I've had the chance to experiment with different carbs, airboots and reed cage. My conclusion is the 133 kit is responsible for the increase in power while the rest of the bolt-on mods only send the powerband higher or lower. I ended up liking best the 133 kit with everything else stock. See for yourself what mods you like best on your bike but it's safe to say the 133 kit is the place to start.
     
  10. bclapham

    bclapham Lifetime Sponsor

    Joined:
    Nov 5, 2001
    Messages:
    4,340
    Likes Received:
    0
    i was cruising eric gorr's website and he has a full 99 cr150 big bore kit for sale, maybe this is the answer to you needs, if you want to go the extra mile with the modifications!
     

Share This Page