Polaris 850/9R — 1150cc Big Bore Stroker Kit

The Godhammer of the 3 kit line Up

Available fall 2025!

We love the Polaris Patriot 850 and 9R platforms. After pushing the limits with the stroker 1000 and the big bore 1070, we decided to take things a little further – and the result is the BIG 1150. This monster has the sound that will make everyone ask wtf is that!!! (check out the sound clip in the pictures below)  It’s our hardest hitting kit yet – stretching your arms like nothing else we’ve built – but don’t mistake brute strength for lack of finesse.  The Big 1150 offers exceptionally smooth throttle control, making all that torque surprisingly easy to manage.  Inspired by the legendary mid-2000s big bores.  If you rode anything over 1000cc back in the day, you already know why we had to bring this beast back to life!

With a gain of 50HP from start to finish over a stock 850, this is the biggest of our engine kits — but arguably the friendliest BRUTE in the fleet!  Designed primarily with the naturally aspirated (NA) customer in mind, there is no reason a boosted application shouldn’t be considered.  Not sure we will have time to develop this engine on the factory boost, but you never know…..  

Key Features

• Up to 220 HP
• “You are now the biggest, baddest SOB in the trees”
• Stroker kit includes the same 78mm billet crankshaft and billet rods used in our 1000 kit
• Compatible with both boosted and naturally aspirated setups
• Can run stock injection and air induction systems

Option for:

• 54 x 52mm throttle body with injector relocate
• 60mm big bore throttle body with injector relocate
• Pump gas compatible — not our favorite, but it’s doable
• Compatible with SLP Twin Pipe Kit
• Big Bore Single Pipe Kit coming Fall 2025

What’s Included in the Kit

• Indy Specialty Bad Ass Billet crankshaft with custom billet rods featuring their proven triple wide PTO bearing setup.  This crankshaft does not flex and PTO bearings do not move around in case – they press fit to crankshaft - $4478.00
• Cast Big bore cylinder 96mm bore - $2800.00
• Billet head c/w domes & new bolts & billet water fittings - $840.00
• 2X Forged Piston kits -  $946.00
• Top End Gasket Kit – $98.50
• 2X piston pin bearing - $100.00
• Stainless coated base gasket - $38.00
• New Primary and Secondary Power Valves to match cylinder - $400.00
• Bigger Injectors with harness - $269.00

Total Value: $9,883.50 CAD

Package Price: $8,500.00 CAD

Crankcase Machining Options

This kit requires crankcase machining to slightly open things up to fit the larger cylinder

- Transfer port case-matching
- Locating ring machining for triple bearing (can Loctite if not machining)
- Add gas/oil mix passages to PTO and MAG bearings — factory blanks these ports and relies solely on direct oiling

*Ask us about exchange crankcases — core return required. *

Optional Add-Ons

• Oil injection delete kit for lightweight builds

• 52mm or 60mm Big Bore Throttle Bodies with injector relocation and custom reed valve adapters

• Fuel Inserts:
  - Pump Gas Insert
  - 100 Octane Insert
  - Race Inserts (110–120 Octane)

• SLP Twin Pipes

• Big Bore Hand-Made Pipes

• Big Bore Single Pipe Kit (Fall 2025)

Why Choose Our Kit?

• Proven crankshaft durability with Indy Specialty billet design

• Engineered for peak performance in deep snow

• Thoughtfully designed for aggressive backcountry riders, flat land speed demons and racers of all kinds

Need help comparing more to a 900?  We are here to answer your questions, overthinkers welcome!