The Yamaha Banshee ATV is one of the most popular ATV's ever produced.  Drawing from the Yamaha RZ350 street bike, Yamaha has created an engine- while somewhat dated in its technology- that has great potential for extreme power output.  After countless hours of testing and assessment Patriot Racing has developed a very robust Banshee engine program.  Current configurations range from simple clean up porting alterations to full-on 500cc+  alcohol set-ups.  Let our experience and testing work for you to determine what set-up is going to best suit your needs. 

    There are several deficiencies in the Banshee cylinder porting arrangement- as mentioned the cylinders rely on older technology.  We've worked very diligently to find where those are and correct them.  We offer a wide range of porting alterations.  The information and pricing is presented to be used as a guideline.  Each motor is specific and custom to your needs.  These guidelines provide a method of outlining which performance level is correct for you and provides some pricing determination.  We offer cylinder kits from 350cc to 500cc+.

Click on the following links to take you to example engine packages:
350cc Moto-cross Engine	350cc Duner
350cc Methanol Drag Motor	350cc Hot Trail Motor
400cc Duner gas motor	417cc Methanol Drag Motor
Cheetah Cylinder Kits 400cc thru 540cc!!!	RZ-Shee Conversions
T-Rex Cylinder Kits 400cc thru 540cc!!!	465cc stock cylinder 10mm stroker

Patriot Racing Billet Head Domes:

    We have created our own billet domes using our computer designed and field tested sets.  Our domes feature the proper design to extract maximum horsepower and torque!  Domes will fit Pro-Design CoolHeads, Performance Trixx (Noss) Heads, and most other billet head designs.  Domes are available for race gas, 50-50 mix, and premium pump gas.  Includes two domes and shipping.  O-ring kits are available as well.

$59.95 delivered (O-ring kits $21.95)

Custom Billet Head Domes:

    We can custom cut domes either from our computer designed and field tested sets, or from your own supplied designs.  Dome configuration is crucial for proper performance.  Domes for gasoline fuels do not work well for methanol!  Dyno testing has shown an increase in HP, torque, and RPM from the proper dome configuration for fuel choice.  Included in the price is the design time, two domes, and shipping.

$89.95 delivered!

Flywheel Lightening:

    A lightened flywheel allows the engine to rev quicker and harder will means explosive holeshots.  However this mod is not recommended for trail riders or our "larger" riders.

$64.95 plus shipping

    Stock Cylinder Head Mods:

    The stock Banshee cylinder head requires modification for even pump gas (92) octane fuel to extract the maximum performance!  We can modify your stock head, not only improving horsepower and torque, but also reduce the risk of engine destroying detonation!  Our head mods are a full head mod.  The squish band and recess are re-cut to target dimensions.  The combustion pocket is slightly reshaped for better performance.  The gasket mating surface is decked varying amounts depending on fuel choice to raise the compression ratio to the target ratio for the octane of fuel chosen. 

$89.95 plus shipping

Billet Round House Bearing Carriers:

    A billet round house bearing carrier makes chain adjustment very easy!  No more busted knuckles trying to adjust the lousy stock bearing carrier.  These billet round house bearing carriers are used with round house style swingarms.  Available for stock axles and for 40mm drag axles!  Cool anodized colors available- purple, red, blue, black.  Also available bare. 

$219.95 Anodized, $194.95 bare.

Kit comes with carrier, all bearings, all seals, and brake caliper mounting plate.  These kits are ready to mount up and run.

    Complete Top End Rebuild Kits:

    Let Patriot Racing supply you with your quality top end components.  We highly recommend the use of Wiseco forged pistons.  The forged piston offers substantial strength increases over the stock cast pistons.  The Wiseco piston design is superior to the stock piston as well.

Top End Kit Price is $289.95 less shipping

Clutch Lock-out Assembly and Cover Assembly

    As the horsepower is increased, keeping the clutch assembly from slipping is a daunting task.  There is a limit to the spring tension available and the forearm strength required to pull the clutch lever!!!  A lock-out clutch assembly uses cam arms that can have weight adjusted for the amount of clamping pressure.  The lock-out assembly uses centrifugal force to apply greater clamping pressure against the clutch pack as the RPM increases.  More RPM, more clamp force = zero clutch slippage.  Can be adjusted to work to shift under throttle but still apply many more times the clamping force against the clutch pack.  Get the horsepower to the ground!  Clutch cover assembly available as a separate item.  Clutch cover assembly required for lock-out assembly to be installed.  The clutch cover assembly allows access to the clutch without having to drain the oil or coolant!!!

Clutch cover assembly, polished w/ exchange $259.95 ($359.95 w/o exch)  Entire cover polished!!!

Clutch Lock-out Assembly $119.95

Package Priced at $359.95 w/ exchangel 

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