350cc Duner Engine

    This is our most popular engine configuration.  Wide power spread with incredible throttle response and much greater peak power- this is a duner's dream.  Whether you prefer to do hillclimbs, cruise the dunes, or race your buddies the Patriot Racing Duner Spec motor is for you.  Horsepower ranges in the upper 60's.

Pipes:

 We highly recommend Toomey T-5 pipes.  If noise limits are a concern our engine package works extremely well with the Toomey Hush Kit. 

Carbs:

28mm Keihin PWKs.  Easy and precise to tune, these carbs are ideal.  By keeping the carb diameter smaller, the intake velocity and fuel atomization is much greater. 

Reed cages:

  V-Force reed cages with the Pro Design V-Force compatible intakes. Or stock boots.  The V Force cage with its W design provides for superior intake velocity, which equates to good throttle response.

Crankshaft Truing and Welding:

The stock Banshee crankshaft must be trued  and welded to prevent crank phase slippage and spreading due to increased power.  This is required for the power output levels of this engine.

Cylinder head:

  An aftermarket billet head with domes for a 15.5:1 compression ratio on race fuel is the best performing.  For premium pump gas motors we modifying the stock head to a 13:1 compression ratio. With the wide-open riding duning often provides- a correct head set-up is important to prevent detonation.

Ignition timing:

  At a minimum the stock stator mounting plate must be modified to provide for at least 4 degrees of timing advance.  The ability of the motor after cylinder porting alterations and the pipes fitted allow for a greater peak RPM- this higher peak does not suit the stock timing curve.  We recommend 4 degrees advance for pump gas motors and 6 degrees for race fuel motors.

Cylinder porting alterations:

    There are several special factors to be accounted for in a good duner engine.  With paddle tires, the load on the engine is much greater, this requires special attention to the torque output.  With the wide-open spaces, more peak RPM is required.  Balancing those two is difficult.  After many different configurations, and many hours of testing, development,  and validation- Patriot Racing has developed an astounding duner engine.  The throttle response and power are very crisp.  The power onset is instant and robust, yet very smooth and ride-able.  As the engine transitions into mid range power, the power increase is substantial.  Finally coming to a higher peak power RPM that makes wide-open riding thrilling- the Patriot Racing duner engine has no match.  Excellent  and robust smooth power coupled with arm stretching peak power- this is our and many of our customers favorite engine.

Package Pricing

Package Priced at: $1795.00

Note package price does not include incidental parts found faulty during tear-down and inspection.

We can build any engine combination, the package pricing is to reflect the complete package available.  Provide us with your budget and we can develop a duner package to meet your budget and satisfy your power needs!!!

Click to go back to the Banshee Page