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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!

  • Cylinder Works Big Bore Cylinder Kit

    Cylinder Works Big Bore Cylinder Kit

    Josh in DE

    Best bang for your buck

    Night and day difference installed on my drz400sm paired with stage 2 hot cams

    Read All Reviews
  • KTM Big Bore Kit

    KTM Big Bore Kit

    Horacio in AZ

    Perfect bolt on!

    I had the shop install it to perfect the jetting with it too. works great. bought one a while ago from a shop and ended up selling the bike. Going to buy one again for my newer XC.

    Read All Reviews
  • Yamaha GYTR Ported Cylinder Head Assembly

    Yamaha GYTR Ported Cylinder Head Assembly

    David in ND

    GYTR Ported Cylinder

    Although this, and everything else that is GYTR, is ridiculously expensive, it fits well, and seems to work well so far. Straight bolt on, with everything included. Only one ride so far, so can't really say if it's durable, but seems to give a little more snort, if only between my ears.

    Read All Reviews
  • 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
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