10734 Kenney Street STE A -Santee, CA 92071 U.S.A - 619-258-6306 - Hours Tues-Fri 8am-5pm - *Closed Sat-Sun-Mon

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Prices subject to change without notice

* Please check back often-New items being developed and added!

Easy Installation · Unlimited Tech Support · Excellent Start Up Performance Mods.

#BK4-3250 $575.00  
·INCLUDES: Complete Fat Boy 4 Exhaust System (with STD Muffler), Jet Kit, Pro Flow Uni Air Cleaner Kit (Flange, Uni Foam Filter and Foam wrap)


·INSTALLATION: 1-2 hours

Stage 1 Power Kits are designed to work with most DRI engine kits.

Stage 1 Bolt-On Kit
S-1 Bolt-On Kit
To purchase the Stage 1 Kit click here  


·INCLUDES: S-1 Bolt on Kit , Complete Fat Boy 4 Exhaust System (with STD Muffler), Jet Kit, Pro Flow Air Cleaner Kit (Flange, Uni Foam Filter and Foam wrap), Vortex X10 CDI, DRI Graphics.


·INSTALLATION: 2-3 Hours *Choice of Graphic color
Blue or Black


To purchase the Stage 2 Kit click here  
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National Kit
Yamaha Raptor 250 “National Kit”
#EK-32RN $1499.00
Raptor 250
National kit
Yamaha Raptor 250 “280 National Kit”

Raptor 250 National Kit

#EK-32RN-280 $1799.00

·INCLUDES: Fat Boy 4 Complete Exhaust System,
 STD Bore Forged Piston or
280cc Big Bore Piston Kit Big Bore Headgasket,Cylinder Strip-Bore-Replate to fit 280cc,
 HP4 Kit (DR Porting, SERDI Valve seat Cut Big Valve Kit, HD Valve Springs, Shortened Bronze Guides, Hardfaced Camshaft),
Instructions, DR Tech Support.

·PERFORMANCE GAIN: 30%-40%+ HP over Stock depending on Camshaft and compression option. ·COMPRESSION OPTIONS: Compression: (STD bore 250cc)  10-1, 12-1
 Compression: (280cc)  10-1, 12-1
CAMSHAFT OPTIONS: (stock core required) Camshaft-Low End/Baja-#87,
Camshaft-Midrange #40, Camshaft- Midrange/Top End #260-X2 (to see options below click here)
·FUEL: 10-1 93 Octane Pump Fuel, 12-1 and up 105-112 Race Fuel Octane ·AIR/FUEL:  Rejet stock carburetor.

*Call for carburetor options.

·AIR CLEANER: Recommend Pro Flow Air Cleaner Kit in stock airbox with no lid.

·CORES REQUIRED: Cylinder, Head, Camshaft

*Cylinder not required on 250cc kit.

NEW CORE PRICING: Head $347.00 , Cylinder $396.00, Camshaft $110.00

Vortex Ignition
Pro Flow AC Kit Foam

3-4 weeks

·NOTES: Kit Price is plus any OEM parts.

Customer must send in to DRI their; Cylinder, Head, (or purchase new cores)


Raptor 250 "280"
National Kit
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FAT BOY 4 Complete Stainless Exhaust System
(with Standard Muffler)

Fat Boy 4 profile
#FB4-EY3250 $499.00  
To purchase the Fat Boy 4 System click here
Fat Boy 4 Exhaust System
*No HQ Muffler Available  
Optional Accessories   

Fat Boy 4-Off


#FB4-4A250 $39.95 Turndown (bolts on with o-ring) 
#06-554  $17.95 Spark Arrestor
(requires turndown) 
1.Turndown bolts on rear end cap, with o-ring seal.
2.To use spark arrestor turn down is required.

*Rejetting is required, with installation of all Fat Boy 4 exhausts.

Fat Boy 4 Turn Down
QP-2 Quiet Tip ** Available in silver only
#FB4-QP-2 $129.95  
Fat Boy 4 w/QP2

·Bolts on rear end cap of Fat Boy · Lowers DB readings a minimum of
2-3 dbs · Forestry approved when used with screen.

* Note: Some rejetting may be required.

To purchase the QP-2 Quiet Tip click here
Fat Boy 4 with QP-2
To purchase Fat Boy 4 Accessories click here
QP2 w/Screen
To purchase Fat Boy 4 Replacement Parts click here
QP 2 with screen
FAT BOY 4 Rebuild Kit

Fat Boy 4 Rebuild Kit A
Muffler "A" Rebuild Kit

Includes: Packing, Core, Screws, O-Ring, Loctite, Decals & Instructions

Muffler "B" Rebuild Kit

Includes: Packing, Screws, O-Ring, Loctite, Decals & Instructions

* NOTE: NO CORE included in Kit "B"

Fat Boy 4 Rebuild Kit B
To purchase a Fat Boy 4 Rebuild Kit click here
Fat Boy 4 Rebuild Kit B
Custom Colored FAT BOY 4 Mufflers * at additional cost

Custom anodized color components (muffler, end cap & turndown) are at an additional cost to the base price for the Fat Boy 4 and the components (Turn down & End cap).

*Available by special order only

**Lead time can be 1-2 weeks
Fat Boy 4 mufflers are available in a Black, Red or Blue anodized finish.
Muffler bodies, rear end caps or turndowns are available colored individually or as a complete package.
*DRI cannot guarantee colored anodized mufflers will not fade over time.

**Custom Color prices are in addition to the regular Fat Boy 4 price Example:
Raptor 250Fat Boy 4 Complete Exhaust System-

                   Custom Colored Muffler and Endcap   +    $114.90  

               Total cost with color option             =    $613.90

Purchase Options : Additional cost of anodizing
#FB4-A3PCO $129.95 3-piece package; Muffler, End Cap and Turndown
#FB4-A1ECO $24.95 End Cap ONLY
#FB4-A1TDO  $24.95 Turndown ONLY
#FB4-A1MFO  $89.95  Muffler ONLY

Custom Blue Fat Boy 4
Custom Blue

Anodized End Caps
Custom Colored End Caps

Colors Available
Custom Colored Mufflers

Colored Turndowns
Custom Colored Turndown

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JE Forged Piston Kits  
JE Forged Pistion Kit
Kit Includes: JE forged piston, pin, clips and rings
STD Bore  
Raptor 250 Piston Kit, 12-1 STD 74.00mm     #273097  $225.00
Raptor 250 Piston Kit, 10-1 STD 74.00mm   #275868  $225.00
Raptor 250 Piston Kit, 13.5-1 STD 74.00mm  #294505 $225.00 JE Piston
*The Above Pistons Require Cylinder Hone
JE Piston 13.5-1
  JE Piston 13.5-1
Big Bore    
JE Forged Pistion Kit
Raptor 250 Piston Kit, 10-1 78.00mm, 280cc 
Raptor 250 Piston Kit, 12-1, 78.00.mm, 280cc
*The Above Pistons Require Cylinder Strip-Bore-Replate
*If customer sends in their stock cylinder the strip bore and replate modification is $295.00
Customer may also purchase new cylinder from DR for $339.00

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Big Bore
Big Bore Kit
Kit Includes: Piston and Headgasket
280CC Kit (10-1)
280CC Kit (12-1)
280CC Kit (13.5-1)
*NOTE: Cylinder must be stripped, bored and re-nikasiled at an additional cost
Replacement Head Gasket    

Replacement Head Gasket
#H-5XT $39.95      
Purchase Examples:    
Customer sends in own Core: $0.00 Customer does not
send in Core:
Strip Bore & Replate $295.00 Strip Bore & Replate $295.00  
Piston $225.00 Piston $225.00  
Headgasket $39.95 Headgasket $39.95  
Total: $559.95 Total: $935.95  
Vortex Ignition  
Raptor 250 Vortex X10 CDI
#VT-3250 $535.00
·Instant Plug-In Performance · 10 Selectable Power Curves · V Boost Booster for Maximum Spark Energy ·Programmable Rev Limit-Race Proven performance and Reliability · 12 Month Warranty from DOM.
To purchase the Vortex click here Vortex X10 CDI
Raptor 250 Vortex X10 CDI
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DRI HP4 Valve Train Kits
· In House Cylinder Porting & Valve Seat Machining · Flow Bench Tested-Big Valves ·Heavy Duty Valve Springs ·Shortened Guides ·High Performance Camshafts
HP4 Kit with DRI Porting & SERDI Valve Seat Machining
#DR-275KP $995.00
·INCLUDES: DR Cylinder Head Porting , SERDI Valve Seat Machining and Professional Head Assembly. Hardfaced Made in the USACamshaft (see cam profile options below), HD Valve Springs w/Titanium Retainers, Shortened Valve Guides, Big Valve Kit (+1.0mm S/S Intake Valve)
*Notes: 1,2,3, 4

HP4 Kit with Porting
·PERFORMANCE GAIN: up to 4 HP* HP4 Kit with Porting
*Results vary depending on camshaft profile and piston compression.  
Customer must send in stock cam core or pay core charge of $110.00  
HP4 Kit without DRI Porting  
#DR-275K $549.00  
·INCLUDES: Camshaft (see cam profile options below), HD Valve Springs w/Titanium Retainers, Shortened Valve Guides, Big Valve Kit (+1.0mm S/S Intake).
* This kit does not include DR porting and SERDI Valve seat cut
**Kit must be installed by a trained professional

*Notes: 1, 3

HP4 Kit w/o Porting
DRI HP4 Kit w/o Porting
·CORES REQUIRED: : Cylinder, Head, Camshaft
·NEW CORE PRICING: Head $297.00, Cam $110.00, Intake Manifold $28.98
·INSTALLATION: Kit must be installed by a trained professional
·DELIVERY TIME: 2-4 weeks
DRI uses hardfaced cams built on stock cores.
Grind Camshaft Grind Camshaft
Part #:260-40B Part #:260-87
Specifications:Midrange Lift: .368”/.368", Duration 270°/268° Specifications: Bottom End Cam, Lift: .353”/.353", Duration 262°/257°
Application: Motocross Application: Baja/Cross Country
Notes: 1,2,3,4 Notes: 1,3
1.Customer must send in stock cam core or pay core charge of $110.00
2.Customer must send in head for modification or purchase new head from DRI.
3.HD Valve springs required
4.DRI custom matches the intake manifold to the intake port on all Raptor 250 heads.Customer must also send in stock intake manifold to be matched to Intake Port Once this process is completed it is unadvisable to change intake manifolds. This custom service is included in the porting process all clients have to do is send in their intake manifold with their head or purchase a new manifold from DRI.
Big Bore Kits and alternate compression ratio pistons are also available to use in conjunction with the HP4 Kit. Check the Big Bore Kit and Piston sections on our site for more info.
Camshafts (stock core required)

Raptor 250 Camshaft
Camshafts sold separately · Hard Faced Made in the USA
Grind options and application notes listed above
*Core charge $110.00 if no useable stock core is supplied
Big Valve Kit

·Kit Includes: O.S Intake
Valve Spring Kits    
HD Valve Springs
HD Springs with titanium retainers. Required with all DRI camshafts
HD Spring Kit with Titanium Retainers #VS-80550 $119.95
  HD Valve Springs
Shortened Bronze Guides #VG-80550 $19.95 ea.
Shortened Bronze Guides
Shortened Bronze Guides

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DRI Clutch Kit

Clutch Kit
Fiber Plates, Steel Plates and Springs

To purchase the Clutch Kit click here
Raptor 250 Clutch Kit
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Pro Flow Kit UNI

Pro Flow Uni
(flange w/Uni w/wrap)
(Uni replacement Filter)
There is no K&N Filter availible for the Raptor 250
To Purchase the Pro Flow Uni Kit click here  
Complete Engine Rebuilding 
(Tear down & Reassembly)

Complete Engine Disassembled
Head Port and SERDI Cut
(includes R & R guide)  
Valve Job 
Flywheel Mod  
Complete Engine Disassembled
Crankshaft Lightening Only #MS-LIGHT $249.00
Crankshaft Balancing ( plus metal) #MS-BAL $250.00
*Customer must supply stock crankshaft-Crankshaft must be in good condition
* Customer must supply gram weight of -piston assembly or piston assembly
New Crankshaft Lightend and Balanced #403-114LB $799.00
* New Crank Supplied- No core required
Raptor 250 Crankshaft
Lobo II Front Suspension
·Made in USA-4130 Chromally Oversized Gullwing Lower A-Arms · Maximum Wheel Travel-Enhanced Steering · Linear Motion Ratios Improves: Braking, Weight Transfer and Corner Stability · Encapsulated Upper Ball Joints · Desert-Motocross-Multiple Shock Options: Elka-Fox-Axis · All Kits Include Crown Steel Braided Front Brake Line Kit
LOBO II F. Suspension Kit


Includes: Lobo A-Arms, Axis or ELKA shocks, Tie Rods, CROWN Brake Lines, Upper & Lower A-Arms come powder coated.
For chrome Plates upper arms add $250.00
For custom powder coat colors in additional charge may apply
“CROWN” Series Brake Lines (Std. or +2)      
Front Std. #CR-6700 $119.95
Raptor 250 Brakelines
Front +2 #CR-6725  $119.95
Rear #CR-6750 $39.95
Available in: red, blue, yellow, smoke, clear 
To purchase the CROWN Series Brake Lines click here
Crown Brake Lines
DR Chrome Front Bumper
DR Chrome Front Bumper

· Made in USA-Mild Steel-Heli-Arc Welded · Triple Plate Chrome · Fit Pre-checked on All Bumper·

* Text Black Front Bumper available by special order only.
Please call for details

To purchase the DRI Chrome Front Bumper click here DR Chrome Front Bumper
ELKA Shocks (for stock a-arms or other brand)
Elka Shock
Call for details and pricing
See chart in Suspension product section for part numbers


Motion Pro  
Motion Pro Throttle
CR Throttle and Cable (stk carb) $49.99
Stock +2 $19.99
CR Cable Stk +2 $25.50
Vortex Cable Stk +2 $25.50
Vortex Throttle Kit $68.77
See chart in Motion Pro product section for part numbers Motion Pro Throttle Cables
DR Block Off Plates
DR Block Off Plates Silver, Blue, Red & Black
DR-PB13 $14.95
To Purchase the DR Block Off Plates click here:
DR Block Off Plates
DR Block Off Plate on Bike
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DRI/ONE Graphic-Seat Cover Kit
DR Graphics and Seat Cover-Black
(Seat Cover No Longer Available)
Black #DR-YAR2GS-BK     $89.95
** Black Graphics temporarily out of Stock*
DR Raptor 250 Graphics Only
Blue #DR-YAR2GS-EB $89.95
DR Graphics and Seat Cover-Blue
To purchase the DRI Graphic Kit click here
DR Raptor 250 Graphics Only
"4-Stroke" Decal Kits (call for colors and availability)
4-Stroke Decals
#DR-874  $19.95
DRI 4-Stroke Decal Kits are 11 in. x 17 in. filled with different sizes of multiple DRI brand logos including; Fat Boy 4, Duncan Racing, DR Icon and duncanracing.com.

Made from high quality 15 mil adhesive, built to last.
To purchase the Decal Kit click here  
DR Number Plates Red

DR Number Plates Black
DR Number Plates (3pc set)
** Please Note: These are the DECAL BACKGROUNDS and not the plastics
WHITE #DR-850 $24.95 Red Black
BLACK #DR-825 $24.95
DR Number Plates Blue

DR Number Plates White
RED #DR-840 $24.95
BLUE #DR-830 $24.95
YELLOW #DR-835 $24.95
GREEN #DR-827 $24.95
  Blue White
DR Number Plates Green

DR Number Plates Yellow
To purchase the Number Plates click here
  Green Yellow

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