E-TEC 850 to 911 Big Bore Engine Kit


Regular price $2,199.00

    • 911 big bore top end kit fits all 2017 850 E-TEC models

    • 190 horsepower!

    • Huge mid-range and torque gain!

    • Hard to keep the skis on the ground!

    • A fuel controller, our performance manifold, and clutching changes are required.

    • For best results, purchase our complete big bore.

    • Turnaround time can vary from 1-15 business days for this kit depending on if core cylinders are in stock. Normal turnaround time is between 3-5 business days.

    • Must send in cylinders, exhaust valves (blades only), and head unless you select to purchase outright.

    • Use this Work Order Form when sending parts so shipping/receiving knows how to identify them. 

  • Part #: ADBM09-203

Cylinder Core Exchange Options(see drop-down menu):

    • Option 1: Purchase Outright - No core cylinder, head or exhaust valves are required to be sent in - Raises kit price by $1600

    • Option 2: Exchange Parts, MUST send your cylinder, head and exhaust valves within 14 business days. As soon as you do, the $1600 charge will be refunded. Exchange parts not received in that amount of time will have no credit applied, and the customer will have to pay for return shipping. 

  • Option 3: Exchange Parts - Your order will be pulled on our shelf waiting for your exchange cylinder, head & exhaust valves to arrive. Once they arrive, we will normally ship the kit within a few business days. No core charge will be applied since we will have your cylinder prior to shipping the big-bore cylinder. 

Low elevation must use our "Big Bore" muffler


Here at the Bikeman Performance state of the art R&D facility, we were excited to get our hands on the 850 E-Tec Ski-Doo powerplant. We were lucky enough to get a pre-production sled to start testing early on. We quickly found out the stroke of the 850 is a massive 80.4mm. This is more than 2mm greater than the Arctic Cat 1000 twin and just under the Mach Z 1000 twin. After running many computer model simulations, we found that the ideal bore size for this engine configuration is 85mm. The 85mm bore puts the overall actual displacement to 912.46 cc. We decided to call this new big bore engine a 911 to dedicate it to the Twin Towers and all those that were affected by the events that occurred September 11th, 2001. Many lives were changed and lost that day so in honor of all the heroes who go to work every day protecting our country and to those who have paid the ultimate price, we salute you.

The Bikeman Performance 911 is a tremendous powerplant making an arm-stretching 190 horsepower and 127 lbs/ft of torque! This big bore setup should be used with a Bikeman Performance big bore muffler at low elevation (0-6,000 ft) to get rid of the extra exhaust flow the 911 creates. Using computer simulations, we knew just about where our port timing should end up so we used it as our starting point. Through many dyno pulls, we made slight adjustments to the porting to further maximize output while maintaining durability. Then it was off to test this engine for a solid year in many applications to prove its longevity. The engine is now ready for the market to help you pull past, out climb, and make your friends feel slow. 

Simply send us your stock cylinder, head & exhaust valves (Blades only please). We will then bore your cylinders, port them, modify your stock head, and machine your exhaust valves. For the best results go with our complete big bore kit which includes everything you need for the big bore motor package.

Kit Includes Exchange Cylinders, Exchange Exhaust Valves, Exchange Head, Pistons, rings, circlips, and wrist pins.

Recommended Options: Power Commander 5, Performance Manifold, & Clutch Kit. If you are running low altitude, you will also want to purchase a BMP big-bore muffler - choose between a trail-friendly Full Velocity or our super light and loud Powder Lite.

***Unless purchasing outright -  you must send in cylinders, head, and exhaust valves (Blades Only)*** Package all contents VERY CAREFULLY and insure the package. BMP is not responsible for damages that occur in shipping. Core parts must be in good, usable condition. Parts not in usable condition will not be credited and the customer will be responsible for return shipping.


Click here to download the general big-bore instructions