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Services
Engine Rebuilding Process
Engine Rebuilding
2-Stroke Porting
4-STK Cylinder Head Center
Custom ATV Builds
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Engine Work Order Form
Shipping Tips
Engine Rebuilding FAQ
Tech Center
Instructions
Technical Documents
Rebuild Process & Shipping
Racing Team
Sponsors
Trackside Support
Apply For Sponsorship
Products
2-Stroke Engine
2-Stroke Engine
4-Stroke Engine
4-Stroke Exhaust
Info & Forms
Shipping Tips
Standard Work Order Form
Engine Work Order Form
Retail Price List
How to Ship your Quad
Credit Card Authorization
Fat Boy 4 Warranty
Dealer Application Form
DRI Terms
Vortex
Vortex Warranty
Purchase Vortex
Vortex ECU Installation and Tuning Tips
Technical Documents
Who Uses Vortex
About
History
Photos
DRI in Print
Contact Us
Duncan Racing International
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4-Stroke Engine
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4-Stroke Bolt-on Kits
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Honda TRX 450R DRI 470/478cc Big Bore Kits
$0.00
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Honda TRX450 ('06-'13) DRI National 500cc Kit
$0.00
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Suzuki LT-R450 "475cc" Big Bore Kit
$0.00
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Suzuki LTR 450 DRI 500cc Big Bore Kit
$0.00
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Raptor 700 DRI 715/727cc Big Bore Kit
$0.00
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Yamaha YFZ 450 (Carb) DRI 470/480 Big Bore Kit
$0.00
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Yamaha YFZ 450 (Carb) DRI 500cc Big Bore Kit
$0.00
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Yamaha Raptor 250 DRI 280cc Big Bore Kit
$0.00
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Honda 400EX-440cc Big Bore Kit
$399.00