Please watch the video below for our recommended engine break-in protocol:

flat lander on a Crossfire

Maps available to download online

and a custom XP5 BMP helix

we would need to replace them at the same time

Big Bore 550cc Replacement Pistons / AC Sno Pro 500 polaris Please watch the video belowLooking for replacement pistons for one of the following big bore BMP motors? Look no further as we have them available for purchase. Sold individually. Comes with rings, circlips and in most cases the wrist pin. *Actual piston may vary from picture* No single action on your part is as important as proper engine break in BREAK IN RESPONSIBILITY Do not operate at full throttle or high speeds for extended periods during the first three hours of use.