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Big Bore KitsBig Bore Kits

Big Bore Kits from Rocky Mountain ATV/MC

High quality off road big bore kits.

Latest Dual Sport Big Bore Kits Reviews – You could win up to $500 for reviewing products!

  • Cylinder Works Big Bore Cylinder Kit

    Cylinder Works Big Bore Cylinder Kit

    Fredrick in FL

    MXA and Rocky Mountain Both said install with no fu...

    But it really needed an ecu reflash on my 17 KTM 250sxf or it wouldn't really run. Sent to Tokyo Mods For reflash, That helped quite a bit, The terrible 17 KTM battery needed to be replaced for a bigger one. and the TPS had to be adjusted. Now with all that done and behind me, IT REALLY RIPS. im about 190lbs and it really helps my corner speed with that little extra oomph, i also went to 14/49 gearing and its pulling great.

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  • Yamaha GYTR Ported Cylinder Head Assembly

    Yamaha GYTR Ported Cylinder Head Assembly

    Eddie in FL

    Looks good but doesn't perform as good as it looks

    For the price it wasn't worth it it was too much bottom end torque you have to ride it very high in RPM

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  • KTM Big Bore Kit

    KTM Big Bore Kit

    Dana in MA

    Buy this if you can.

    Was bummed about the cost, but was happy when I got it. Was pleased to receive a KTM power parts head with insert which I was not expecting. Came with everything needed then some. Bike runs mint.

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  • Wiseco Big Bore 440 Kit

    Wiseco Big Bore 440 Kit

    brandon in OH

    Great big bore kit for the ltz 400

    Very great product huge power gain

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