2010 Polaris 800 Piston kit Dragon Switchback Pro RMK fix it durability kit - FORGED

CYLINDER IS OPTIONAL

** NOT FOR USE IN TURBOS **

THIS KIT INCLUDES FORGED MCB DUAL RING PISTONS!
This is a complete top end piston kit for the 2010 Polaris 800 monoblock CFI Dragon / Switchback / Pro RMK / Assualt all 2010 monoblock CFI motors. This kit is designed for improving the reliability / durability of this motors design. It used .240" taller pistons, with tighter tolerances and less skirt taper. This reduces the piston "rock" or "slap" improving the reliability of this motor. This kit includes taller pistons, dual rings, pins, clips, wrist pin bearings, complete top end gasket kit, (factory style coated metal gaskets), machined .240" shim and the extra base gasket for the other side of the shim, Four new .240" longer bolts (not shown), instructions for installation with torque values. We have this kit in our own 2009 Dragon 800 with 2900 miles on it so far, and no issues same compression as when installed. We off the same kit for the 2010 and newer, see our other auctions. Our kits come with full instructions and torque values, we offer service before, during and after the sale.

Polaris 800 CFI fix it explanation

The stock 800 CFI motor runs a piston that is a total height of 2.885". The stock piston to cylinder wall clearance on the CFI motor runs from .0070"-.0090", this is considerably larger than the typical piston to cylinder wall clearance of most other water cooled two cycle engines of .0045". The stock piston also has a considerably larger taper from bottom to top .0026". These three main factors (short piston, larger piston to cylinder wall tolerance, and larger taper top to bottom) allows the piston to rock or slap within the cylinder. This results in premature ring wear, loss of compression and eventually piston skirt failure or cylinder skirt failure. The MCB fix it kit uses a piston that sets the piston to cylinder wall clearance at .0055". It uses a piston that has significant less taper, and is .240" taller or 3.125" total height. These three factors eliminate the rock or slap described above, improving the reliability. Stock fuel mapping on several 800 CFI years is very lean as it can be for emissions. This causes "hot spots" in the fuel mapping and can cause any piston to swell quickly. You can have your local dealer update your flash or use an aftermarket tuner.



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