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Big Bore KitsBig Bore Kits

ATV Big Bore Kits

If you want to get more power out of your ATV, you can’t go wrong with a big bore kit. It’s a quick way to increase your engine displacement for more horsepower. For example, a Honda 400EX big bore kit will increase the engine displacement from 400 cc to 440 cc. This offers an immediate power gain.

We carry several brands that manufacture ATV big bore kits, including Wiseco and Cylinder Works. Both are respectable companies that make excellent products. For most machines, only one or the other is available (if any at all). How can you know what will work for your quad? The only way is to use the Parts Finder with your ATV’s make, model and year. Fortunately, big bore kits are available for many popular quads, including the Raptor 700, TRX450R, Z400 and many others.

If you’re looking for a little more power, a big bore kit is the way to go. And when you want to find a great price from a leading supplier, Rocky Mountain ATV/MC is your source. We have highly acclaimed customer service and policies in place to make sure your shopping experience is the best it can be. Pick up an ATV big bore kit today to find out for yourself!

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

  • Wiseco Big Bore 440 Kit

    Wiseco Big Bore 440 Kit

    TROY in CA

    Best mod ever

    This was buy far the best upgrade I did to this quad. Great fit.

    Read All Reviews
  • Cylinder Works Big Bore Cylinder Kit

    Cylinder Works Big Bore Cylinder Kit

    David in Texas

    365cc for KTM 350sxf...buyer beware

    Cylinder kit goes together nicely, but Cylinder Works gave no support after the installation of this kit. The kit obviously changes the fuel needed, which will require a ECU software change, they offer zero support except a jpeg of suggested settings.

    Read All Reviews
  • Dubach Racing Engine Relocation Kit

    Dubach Racing Engine Relocation Kit

    KEVIN in UT

    Easy Install

    Smooth instal.Take your time and follow the instructions.Made minor improvemen to the bike handling

    Read All Reviews
  • Athena Big Bore Kit

    Athena Big Bore Kit

    DAVID in CA

    Athena 290 big bore wr/yz

    I have ran this big bore for three years and have great success with it, makes great bottom end and mid range power. I have ran it on my 08 yz250f with a wr trans and rekluse clutch and hot cams, awesome woods bike.

    Read All Reviews
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