BMP Polaris 800 RZR/Sportsman/Ranger 82mm Big Bore Kit

BMP Polaris 800 RZR/Sportsman/Ranger 82mm Big Bore Kit


Regular price $1,199.00

  • Big bore kits for 2006-2014 RZR/Ranger/Sportsman 800 Models

  • Brings your 760cc motor to a true 800cc

  • Increase horsepower and torque

  • Big horsepower gains when combined with other modifications

  • Kit uses high quality Wossner German forged pistons

  • 10.5:1 Compression Ratio

  • On a bone stock machine no EFI controller is required, but you will run safer and pick up power with one

  • Exchange cylinder keeps prices reasonable

  • Kit includes: 82mm pistons, rings, circlips, wristpins, 82mm gasket kit, bored & nikasil plated cyilnder

  • Recommended options: BMP head porting, BMP high performance cam, BMP performance exhaust, Power Commander 5, Stage 2 clutch kit, and BMP high flow intake kit.

  • Use this form when sending in engine work: BMP WORK ORDER FORM

  • 2004-10 Part #: 12-301

  • 2011-14 Part #: 12-302


Cylinder Core Exchange Options(see drop down menu): 

  • Option 1: Purchase Outright - No core is required to be sent in - Raises kit price by $400

  • Option 2: Exchange cylinder, send yours back with 14 business days. As soon as you do, the $400 charge will be refunded. CORE MUST BE SENT BACK WITHIN 14 BUSINESS DAYS. If no core is received within 14 business days no credit will be applied. 

  • Option 3: Exchange cylinder - Your order will be waiting for your cylinder to arrive. Once it does, we will ship the kit. No core charge will be applied since we will have your cylinder prior to shipping the big bore cylinder. 



Increase your horsepower and torque with this big bore kit from BMP! We bore out your stock cylinders to 82mm, and send you on your way with a Cometic gasket kit. The extremely high quality forged Wossner pistons are available in a 10.5:1 pump gas compression ratio.  This is an exchange cylinder program, however you may purchase the kit outright for only $400 extra!

Head porting, high performance cam, performance exhaust, power commander and clutching are recommended options. You can run the big bore cylinder on a 100% stock setup, but it will run a little on the lean side. Since dirt ingestion is the #1 cause of motor problems in the RZR 800, we recommend our high flow intake kit. 

Please fill out our WORK ORDER FORM and send engine work to:

Bikeman Performance
920 Pine Street
Saint Croix Falls, WI 54024

Watch the video below for proper engine break-in protocol: