Building a pro level WORCS race quad

By the staff of Dirt Wheels, Photos by Pat Carrigan

The GBC tires and Goldspeed Beadlock wheels are a great combination. Tire Blocks let Logan keep riding after a tire puncture.


Logan Huff has dominated his Pro-Am ATV class competition in the World Off-Road Championship Series (WORCS) for the last two years. He landed his second Pro-Am championship in 2018 and made his Pro class debut at the first round of WORCS in Primm, Nevada. Huff decided to make his first WORCS Pro showing on a fresh Yamaha YFZ450R build. We got to catch up with him and cover this build the day before he shifted his YFZ into gear on the starting line of the first round of the 2019 season!

A Duncan Racing oil recovery tank, Works Connection engine plugs, FW Carbon frame guards, Glann Innovations case saver, and more can be seen here.


Yamaha’s YFZ450R is impressively fast off the showroom floor for most riders, but a pro rides at a level most of us dream of. Power upgrades were in order, so Logan installed a Cylinder Works standard bore high-compression piston and cylinder kit. Fastheads ported and polished the cylinder head and cut the valve seats back to spec. Huff then installed a Stage 2 Hot Cams exhaust camshaft and left the intake cam stock.

Horsepower is a pro racer’s friend. All of the engine upgrades made this quad very fast.

The engine was then filled up with Syn Blend Ester 10W-40 oil from Maxima. A Duncan Racing oil recovery tank was added to the build. The cooling system gained CV4 radiator hoses, and the system was then filled with Engine Ice coolant. 

FMF has Logan covered with their impressive Factory 4.1 muffler that is attached to a stainless steel header.


External engine mods began with an FMF Racing Factory 4.1 full exhaust system that includes a blue-anodized muffler with a carbon fiber end cap and a stainless Powerbomb header. Logan’s Yamaha gained a Fuel Customs intake, paired with a Twin Air reusable foam air filter. A Vortex fuel controller allows Huff to change the fuel-injection system’s mapping. He had PEP massage the mapping system and help tune his quad to put out 43 horsepower with the use of VP Racing fuel.

The stock clutch on a Yamaha YFZ450R works well, but racing puts a lot more strain on parts. A fresh Hinson Racing complete conventional clutch kit replaced the stocker and can handle a lot more abuse.

Campbell Racing Fab, RPM, Sunstar, Lonestar Racing, Galfer USA, and more have Huff’s rear end covered here.


Running a race on some of the roughest courses in WORCS requires great suspension components. The front end of Logan’s YFZ450R sports Roll Design’s long-travel control arms adds width, travel, and ground clearance to the Yamaha. A set of Elka Stage 5 shocks were bolted up. A set of extended Galfer steel-braided brake lines paired up with Lonestar Racing brake line clamps on the new arms. A Roll Design anti-vibe steering stem and handlebar clamp pair well with a set of Fasst Co. Flexx handlebars that act as an extra inch of travel.

The rear end gained a new suspension linkage frame brace from Walsh Race Craft. A Roll Design linkage added a bit more travel in the rear with a supple Elka Suspension Stage 5 shock. Huff got a hold of a fresh RPM Dominator II axle to install on his freshly C&J powdercoat swingarm.

A Hinson clutch fades less and has great engagement. The Fasst Co. brake return spring and clevis are a nice touch.



The parts list keeps adding up when you need to make your quad work well and protect it from race abuse. Huff went to Campbell Racing Fabrication for a 1/2-inch-thick poly underbelly skid plate for his Yamaha. The swingarm gained a 3/4-inch poly sprocket guard from CRF and a rotor guard from Snurr Interlocking. The new chain and sprockets came from Sunstar with a stock gear ratio. A Glann Innovations chain slider and case saver add more protection to the drivetrain. 

A Fasst Co. Flexx bar cuts down on vibration and more, just like the Roll Design stem and bar clamp. An IMS dry-break fuel tank allows for a quick refuel during long races.

Logan installed carbon fiber frame guards on his YFZ from FourWerx carbon. He also mounted up a number plate and got them to recover his quad’s seat. Huff went to Rath Racing for a front and rear bumper and installed a set of their Competition nerf bars with heel guards. The teeth on the Rath pegs are very sharp and keep your feet where you need them.

Roll Design long-travel A-arms paired with Elka Stage 5 shocks provide a supple ride.


Huff moved onward to the handlebar, where he bolted up a set of PowerMadd handguards, along with ProTaper Pillow Top grips for hand protection and grip. A Pro Design ATV kill switch keeps the YFZ from wandering if Logan gets booted off during a race.

Finally, a set of GBC Ground Buster III rear tires and XC Master front tires are wrapped around Goldspeed Beadlock wheels with a 4:1 offset. Tire Blocks are stuffed inside Logan’s rubber, and they let him keep rolling if something punctures his tires.

FourWerx Carbon stitched up this ribbed seat cover that matches the color scheme of the Yamaha.


Elka shocks paired with Roll Design arms and linkage are one of the best suspension combinations around for sport ATVs. The ride was buttery smooth over the roughest sections. Logan’s setup allowed us to land big jumps, rip over deep whoops and cruise over rocks and square-edge holes pretty easily. The Flexx bar, RD anti-vibe stem, and clamp soaked up vibration and chop, which cuts down on getting arm pump.

FourWerx Carbon stitched up this ribbed seat cover that matches the color scheme of the Yamaha.


Rath’s pegs and nerfs always offer great foot traction, but it’s a good thing the engine is loud enough to cover the sounds of the soles of our boots crying. The FW Carbon seat cover is a nice touch, and it is easy to move around on while also holding us in place. One of the most impressive parts of this build is the power output!

The engine absolutely breathed fire and pumped out torque. The power comes on instantly, and the traction from the GBC tires transfers it to the ground quite well. All of the engine upgrades and tuning from PEP gave this quad the boost of horsepower and torque that you need to stay competitive in pro quad racing. 

GBC Motorsports Ground Buster III tires’ rounded profile lets them slide well and still offers great traction. The Goldspeed wheels are tough.



Logan Huff is a force to be reckoned with. He is rising through the ranks and is now playing with the big boys at the pro level at WORCS. His builds continue to escalate as time goes on. Eventually, we hope to see Huff standing on the top step consistently in pro, as he did during his back-to-back Pro-Am championships!

SSi Decals did a great job on this graphics kit. C&J Powdercoat took care of the frame and more.



ANTIGRAVITY BATTERIES: www.antigravitybatteries.com, (310) 527-2330

8-cell OEM replacement $179.99

CAMPBELL RACING FABRICATION: www.campbellracingfabrication.com,
(435) 632-4902

1/2-inch skid plate $110

3/4-inch sprocket guard $65

C&J POWDERCOAT: www.cjpowder.com, (435) 673-6565

Powdercoat + sandblasting $860

CYLINDER WORKS: (515) 402-8000, www.cylinder-works.com

Standard Bore HC cylinder kit $539.95

DUNCAN RACING: www.duncanracing.com, (619) 258-6309

Oil recovery tank $139

ELKA SUSPENSION: (800) 557-0552, www.us.elkasuspension.com

Stage 5 front shocks $1,724.99

Stage 5 rear shock $1,309.99

ENGINE ICE: www.engineice.com, (877) 806-9377

1/2-gal. bottle $29.95

FASST CO.: www.fasstco.com, (877) 306-1801

12-degree Moto Flexx handlebar $359.99

Red bar pad cover $10

Rear brake clevis $39.99

Rear brake return spring $19.99

FASTHEADS: www.fastheads.com, (435) 668-7776

Port & polish $245

Valve seat cut $175

IMS PRODUCTS: www.imsproducts.com, (800) 237-9906

3.8 Gal. dry-break tank $274.95

FMF RACING: www.fmfracing.com, (310) 631-4363

Full Factory 4.1 RCT anodized/ carbon end cap $699.99

FOURWERX CARBON: www.fwcarbon.com, (262) 501-9696

Carbon fiber frame guard set $90

Carbon fiber rear number plate $65

Seat cover $158

GBC MOTORSPORTS: www.gbcmotorsports.com

XC Master front tire $59.26 ea.

Ground Buster III rear tire $91.06 ea.

FUEL CUSTOMS: www.fuelcustoms.com 

YFZ intake system $325

GALFER USA: www.galferusa.com, (805) 988-2900

Front brake line kit $71.95

Rear brake line $32

GLANN INNOVATIONS: www.glanninnovations.com, (515) 528-9056

Case Saver $80

Chain slider $65

GOLDSPEED PRODUCTS: www.goldspeedproducts.com,  (702) 643-8473

Victory Box-3 $547.90

HINSON RACING: (909) 946-2942, www.hinsonracing.com

Complete conventional clutch kit $1084.99

HOT CAMS: www.hotcamsinc.com, (515) 402-8000

Stage 2 exhaust camshaft $199.95

LONESTAR RACING: www.lsracing.com, (480) 834-2990

Brake line clamps $32.95 a set

E-brake block off plate $11

PRO TAPER: www.protaper.com, (951) 736-5369

Pillow Top ATV grips $12.95

MAXIMA RACING OILS: www.maximausa.com, (800) 345-8761

Syn Blend Ester –  10W-40 $11.03 a quart


tunning $450

PRO DESIGN RACING: www.prodesignracing.com,  (714) 534-0620

ATV kill switch $34.95

POWERMADD: www.powermadd.com, (651) 462-8465

Star Series handguards $35

Star series ATV mount kit $40

RATH RACING: www.rathracing.com, (320) 234-7223

Front bumper $124.95

Rear grab bar $119.95

Competition nerf bar $464.95

ROLL DESIGN: www.rolldesign.com, (760) 731-5920

Long-travel control arms $1,495

Powder coating $95

+1 forward, +1 tall anti-vibe  steering stem $299.95

Anti-vibe bar clamp $99.95

Linkage $100

RPM: www.team-rpm.com, (928) 771-9363

Dominator II axle $389.99

CV4: No contact info

Red radiator hose kit $80.99

SNURR INTERLOCKING: www.p4quads.com, (330) 345-1406

Poly rotor guard $50

SSI DECALS: www.ssidecals.com, (877) 955-7446

Custom kit $199.95

SUNSTAR: www.sunstar-braking.com, (937) 704-1462

520XTG-120 Works chain $114.95

Powerdrive countershaft  sprocket $23.95

Rear steel sprocket $34.95

TIRE BLOCKS: www.ridetireblocks.com, (253) 973-5111

21×7-10 kit $100 a tire

20×11-9 kit $137.50 a tire

TWIN AIR: www.twinair.com, (800) 749-2890

Air filter $38.95

WORKS CONNECTION: www.worksconnection.com, (530) 642-9488

Engine plug kit $39.95

Clutch perch $155.85

WALSH RACE CRAFT: www.walshrc.com, (386) 364-4942

Linkage frame bracket $150

Lowered subframe $600

Footage studs (for Rath pegs 1.125”) $200

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