Additional Images

2012-17 Polaris 800 Piston kit Switchback Pro RMK Stage 3 Rebuild Kit - CAST

2012 2013 2014 2015 Polaris 800 Piston kit Switchback Pro RMK Stage 3 rebuild kit w/ Cylinder & Crankshaft

IF YOU ARE ORDERING FOR A 2016 OR NEWER THERE ARE TWO POSSIBLE OPTIONS FOR YOUR CRANKSHAFT SEE DROP DOWN MENU AND PHOTOS!!!! . This is a complete Stage 3 rebuild kit for the 2012-2015 Polaris 800 monoblock Switchback / RMK all 2012/15 monoblock CFI motors. This kit is designed for improving the reliability / durability of this engines 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 custom pistons, dual rings, pins, clips, wrist pin bearings, complete engine gasket kit, (factory style coated metal gaskets), machined .240" shim and the extra base gasket for the other side of the shim, eight new custom longer bolts , two taller dowel pins, as well as a re-manufactured cylinder, and instructions for installation with torque values. Stage 3 also includes a Professionally Remanufactured crankshaft fit for 2012-2015 Polaris 800! We have this kit in our own 2015 Assault 800 with 4100 miles on it so far, and no issues same compression as when installed.

Polaris 800 CFI Motor Cylinder Casting Numbers:
2008/2009 =3021843
2010 =3022201
2011 =3022205
2011 MID - 2014 = 3022205 / 302249 / 3022352 / 3022828
^Could Be Any of These^
*Basic changes were cylinder skirt wall thickness*

Fits all Polaris two cylinder 800 monoblock motors for 2012/2017. Call or see our other auctions for 2010-2011.

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 is as lean as it can be for emissions. This causes "hot spots" in the fuel mapping and can cause the piston to swell, this is why we have developed an optimized cylinder wall clearance with our proprietary piston design . We also recommend the use of Ice Scratchers to optimize the cooling of the motor and eliminate the "hot spots" that can cause cold seizure like failures, especially if ran at the tighter tolerances other than what we MCB recommend.

Pricing: $1,599.95

Customize Your Item

- Crankshaft Type -
 * required
- Core Returns -
 * required
- Crankshaft core Fee -
 * required
- Cylinder Core Fee -
 * required
- Select Cylinder Casting Number -
 * required


2012-15 Polaris 800 Piston kit Switchback Pro RMK fix it kit w/ cylinder


  • 20778126
  • 20778126
  • MCB
  • New

Shipping Information

  • Item Requires Shipping
  • 46.0 lbs.
  • W22.0000” x H18.0000” x L12.0000”

Customer Reviews

Comment Total Reviews (0)

Write the First Review!

You must login to post a review.

Share 2012-17 Polaris 800 Piston kit Switchback Pro RMK Stage 3 Rebuild Kit - CAST on Facebook