EXTREME BUILD: AVINA PREP 472cc BANSHEE

On Dec 25, 2024

AVINA PREP 472cc BANSHEE

Inexperienced riders need not apply! By the staff of Dirt Wheels

It’s been said that “the Yamaha Banshee is not a race quad.” And it was probably a non-racer who said that. Designed in the mid-1980s, the twin-cylinder two-stroke ATV’s engine was based on those from the RD350 and RZ350 street bikes, the latter of which was a very popular “café racer” with liquid-cooling and an exhaust expansion chamber. In 1987, the first year of Banshee production, Dean Sundahl and Craig Corda won the Baja 1000 on one. Since then, we’ve seen many competition and higher-performance Banshee builds at Dirt Wheels, and this one is right up there with the best of them.

THE BUILDER

Kevin Avina is a former desert racer from a time when ATV racing saw far more pro ATV entries than we currently see. Kevin also owns Avina Prep, which builds dream machines like this Yamaha Banshee. Over the last four decades, Avina has also been servicing, fabricating and assembling race quads for big-name racers like Josh Row, Mike Cafro, Jimmy Stephenson, Josh Frederick, and many more.

“The owner of this Banshee lives in New Jersey, and he wanted to build a desert machine/WORCS racer,” said Avina. “That’s why we have 23-inch tires on the front and 22s on the rear, as well as the bigger gas tank.” But, this build goes far beyond bolt-on mods, so let’s dig in!

**ITP Holeshot XCT tires in typical desert sizes get the power to the ground. DWT beadlocks are necessary for this much thrust!**

“I WANNA GO FAST!”

Specializing in the Yamaha Banshee, Redline Racing built the 472cc Super Serval top-end using 72mm Wiseco pistons. It’s ported for all-around power, the cases are port-matched, and it uses a Redline Racing Cool Head. Dual 35mm Keihin Air Striker carburetors feed the engine with a healthy dose of VP Racing C12 race fuel and Maxima Super M 2T mixed 32:1. The stock airbox (wrapped in gold heat-shield material) is used without the lid but with a Pro Design Pro Flow Kit and K&N filter with an Outerwear. On the other side of the carbs, we spotted V-Force 4 reed valves with UPP intake manifolds.

“Lenny and Loren at Duncan Racing helped me tune it, and I appreciate them doing that without it being their product because it runs well,” said Avina. Avina had just installed Kenny Roberts Pipes (KRP) at the customer’s request. They tested with a few other exhaust systems before the KRPs with some impressive results. On a dyno, Cam Sawyer at Redline Racing tested the Banshee with POD filters and Sniper Pipes, and got 108 horsepower and 58 pound-feet of torque; CPI Pipes made 99 horsepower and 56 pound-feet; and FMF Fattys produced 95 horsepower and 57 pound-feet. They had yet to dyno with KRPs.

**The new owner chose the colors for this build, emphasizing gold accents. The see-through clutch cover from Direct Drive is the main focal point.**

GEARED UP

A welded 4mm stroker crank mates the top to the bottom end. Behind the Direct Drive Lockup see-through clutch cover, there’s a Redline Racing Pro Mod transmission with a Redline Racing Lockout clutch system, straight-cut drive gears, and a Redline Racing Shift Star for smoother shifting with a high-horsepower engine. The final gear ratio is 15/40 using Sunstar sprockets and a D.I.D chain.

RUBBER SIDE DOWN

This Banshee corners, that is, if you can keep the front end on the ground. Avina installed Roll Design +2 long-travel A-arms. The upper arms are for a YFZ450R to accommodate the Yamaha YFZ450R OEM spindles and Baldwin Motorsports Billet hubs for enhanced turning. The shocks are PEP PB1 dual-rate fully adjustable units tuned by PEP owner and suspension master Wayne Mooradian.

At the rear, we spotted a rare Roll Design swingarm. “You can always spot a Roll Banshee swingarm because they have the dip to clear the shock bolt,” said Avina. The rear shock is a PEP ZPS dual-rate fully adjustable unit with a large Dakar reservoir. “Wayne at PEP gave me the shock mount that he uses, and then I fabricated a piece of aluminum to bolt it to the frame, and it came out super clean,” said Avina. The linkage is OEM anodized in gold.

SHREDDER!

An RPM axle carrier and gold anodized axle nut were fitted with an RPM Dominator II axle, extending the rear width by 4 inches over stock. DWT beadlock wheels are at all four corners with gold anodized rings. ITP Holeshot XCTs offer superior grip with an aggressive lug that can handle warp speed.

**From the top: Duncan Racing chrome front bumper, TM Design belly skid, Pro-Tect stainless steel swingarm skid, and an old-school PRM grab bar in chrome. The rear shock link is stock anodized.**

TEST RIDE

The Banshee roared to life first kick with an intimidating growl as we let it warm up. The work done to the bottom end is immediately evident with smoother shifting than we remember from a stock Banshee transmission. It’s powerful everywhere, but the signature Banshee hit from mid-range to top speed is seriously amplified; you learn quickly to keep your weight forward as those ITP Holeshots dig in. If you can keep the wheels planted, it turns precisely and corners predictably, even in the tight stuff!

Our test rider was SCORE Baja series racing veteran Efren Vazquez from Guerrero Negro, Baja California Sur, Mexico. Despite his experience, he’s too young to remember the two-stroke era of sport quads. “I was very excited because this is the first two-stroke quad I’ve ever ridden,” claimed Vazquez. “It’s an amazing quad. It has a lot of power, and I think for desert racing, this Banshee would be perfect, especially for the higher speeds of Baja.”

**This Banshee demands an experienced rider who can handle unlimited raw power, but even then, you better treat it with respect!**

That’s a Roll Design swingarm. An RPM Dominator II adjustable axle with carrier and axle nut widens the rear stance by 4 inches. Kevin Avina fabricated the mount for the rear PEP shock reservoir clamp.

One Banshee complaint we’ve heard over the years is that they don’t turn as well as other sport quads. Roll Design front suspension and PEP shocks fix much of the problem—if you can keep the front wheels down!