Quads

 

Services

Yamaha Banshee

The Yamaha Banshee is the most heavily modified quad of all-time. We build each kit to match your power preference and riding style. Arlan is know for having the most usable power delivery in the industry. Whether you are getting your cylinders ported or building a 530cc monster, you can be sure that the final result will get the adrenaline flowing and put a smile on your face. Check out the details below on these power products for the Honda TRX250R. 

Performance Steps

Step 1 : Exhaust System & Jet Kit ~ 9HP

Step 2: V-Force 3 Reed Vavle System ~ 1HP

Step 3 : Advance Timing ~ 2HP

Step 4: Increase Compression via Milling or CoolHead ~ 3-4HP

Step 5 : Cylinder Porting ~ 8-12 HP Depending upon Rider's Preference (Drag, MX, ect...)

Step 6: 30mm Carb Kit ~ 2HP

Step 7: Case Match Transfer Ducts to Cylinder ~ 2HP

** At any point in the process, you should consider getting the Crankshaft Trued & Welded to prevent spreading and twisting.

 

 

 

 

Performance Products

Carburetors: We take 28mm PWKs and taper-bore them to 30mm and they match perfectly with V-Force reeds for outstanding throttle response.

Pro Design Product : We carry a full line of Pro Design Racing products to get your Banshee set: From CoolHeads to Adjustable stator plates, we have you covered.

Reeds : The V-Force 3 reed cage maximizes surface area and matches to the carburetors above for maximum performance.

Replacement Pistons: We have pistons for OEM cylinders, OEM Big-Bores Resleeves, NIKS Cylinders, and more...Call us today and let us know what you need.

Replacement Crankshafts: HotRods stock stroke or +4mm stroker cranks come complete with HotRods connecting rods, top-end bearings, and crankshaft webs.

Performance Services & Engine Kits

Head Modification : We mill the cylinder head for optimized combustion and increased compression. We can also smooth out pitting from previous detonation.

Cylinder Porting : Each cylinder set is ported to match the Rider's preferences. We optimize port shapes and timing to deliver significant power upgrades and throttle response.

Yamaha 350 Banshee Port Modifications 

An important step we do when porting Banshee cylinders is to cut boost ports into the cylinders. These ports are also called Boyesen Ports, named after Ivan Boyesen who first patented this design . The ports improve intake area and improve performance by increasing crankcase filling. Adding the boost ports increases midrange and top end hp.

As shown we machine these ports on a milling machine to insure size angle and placement.

Porting the cylinder

Because acceleration is so important We concentrate on improving efficiency and improving scavenging in the cylinder. While it is true that long duration port timing can make a lot of horsepower, that type of engine is hard to ride and has a very narrow power band. We have found that controlling the fuel charge with proper transfer port design allows us to make the big horse power, but give the advantage of a much wider power band.  Of course we improve the shapes of the exhaust and intake ports as well. Each cylinder is ported to meet the needs of the individual rider. LED porting is much more than a big tall exhaust port!

 

An important part of banshee porting is matching the center case transfer passages  to the transfer duct entries on the bottom of the cylinders. Stock the cases a badly mismatched to the cylinders. The photo below on the left shows the scribe marks we have laid out to grind to the correct this mismatch. As you can see a lot of material will need to be removed. The photo below on the right show the cases after being port matched to the cylinders.

 

Because we often double the horse power on a 350 Banshee build the crank shaft needs attention also. We true the crank shaft so it runs true in the case. To much run out in the crank means that the shaft wobbles . This causes vibration friction and will eventually cause a failure of both e cases and the crankshaft. We then wield the crankpins to prevent the flywheels from moving on the crank pins. This helps keep the crank true and prevents twisting or spreading under hard use.