PROJECT YAMAHA YFZ450R
— Building a pro level WORCS race quad —
By the staff of Dirt Wheels, Photos by Pat Carrigan
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!
MOTIVATE THE MOTOR
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.
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.
External engine mods began with a 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.
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 that add 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 like 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.
WORKS FOR WORCS
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.
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.
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.
WHAT A RIDE
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.
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 transfer 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.
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, like he did during his back-to-back Pro-Am championships!
PARTS & CONTACTS
ANTIGRAVITY BATTERIES: www.antigravitybatteries.com, (310) 527-2330
8-cell OEM replacement $179.99
CAMPBELL RACING FABRICATION: www.campbellracingfabrication.com,
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
PEP PERFORMANCE TUNING: (909) 477-7025
PRO DESIGN RACING: www.prodesignracing.com, (714) 534-0620
ATV kill switch $34.95
POWERMADD: www.powermadd.com, (651) 462-8465
Star Series hand guards $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
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