Please select make, model and yearBig Bore Kits
High quality off road big bore kits.
Jacob in TN
Very dissappointed in the knowledge of the RM sales team. They told me that all I would have to do (to my 2004 400ex) was press out the old sleeve and press the new one in, however that was not the case. The machine shop had to press out the old one, bore and counter bore the cylinder in order to press the new sleeve in, then after getting the cylinder back I went to put it all together just to find out that the sleeve had to be bored to the piston also. Wasn't very costly to have done ( about $120) but would've been nice to have known all this from the start. Wisecos 440 big bore kit is the bomb tho, along with hot cams stage 2 cam and a dyno jet jet kit my quad is wicked fast.Read All Reviews