Dirt Bike Big Bore Kits

Most Recent Big Bore Kits Reviews

Athena Big Bore Stroker Kit Athena Big Bore Stroker Kit 5150 5 out of 5 stars 112 Big Bore stroker kit "This kit was pretty straight forward to install. This kit states no machining necessary but you will need to shave the case in order to clear the piston. Also it states all gaskets are included for the job, that not accurate, it comes with head and cylinder gaskets only. Took the bike out for the first time yesterday and it is a rocket. It makes allot more bottom end and the power band is incredible. Used Athena's recommendation for the jetting and it was pretty close just need a little fine tuning. I would recommend this for advanced riders; the yz is fast out of the box and even faster with this mod Time will tell on durability."
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Athena Big Bore Kit Athena Big Bore Kit edgrrr 5 out of 5 stars Great Bark "I have 2 2004 CRFs, one stock and one big bore. Big difference in power and really aggressive bark. Much more torque on hand. You have to have intake valves on spec to start the extra displacement. I may go for kibblewhite valves to keep the compression over time."
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