INTRODUCTION The XRAY XB8 is a modern, high-competition premium luxury racing 1/8 nitro off-road car that is the epitome of high-performance and fine distinctive design. Your XB8 offers highest performance, responsive handling, and traditionally exceptional XRAY quality, engineering, and design. The superb craftsmanship and attention to detail are clearly evident everywhere on the XRAY XB8.
IMPORTANT NOTES – ELECTRICAL • Insulate any exposed electrical wiring (using heat shrink tubing or electrical tape) to prevent dangerous short circuits. Take maximum care in wiring, connecting and insulating cables. Make sure cables are always connected securely. Check connectors for if they become loose. And if so, reconnect them securely. Never use R/C models with damaged wires. A damaged wire is extremely dangerous, and can cause short-circuits resulting in fire.
SYMBOLS USED Part bags used Assemble in the specified order ➊ ➋ ➌ Cut off shaded portion Use special tool Assemble left and right sides the same way Assemble front and rear the same way Pay attention here Apply instant glue 2x L=R Cut off remaining material Assemble as many times as specified (here twice) Time Use cleaner or WD-40® Tighten screw gently CA Apply oil Apply grease Apply threadlock Follow tip here Follow Set-up Book OIL Ensure smooth non-binding movement Use pliers SET-U
XB8 TECH TIPS TIP FRONT & REAR DIFF GEAR MESH ADJUSTMENT If there is too much or too little diff side play, this may create non-optimal gear mesh between the diff gear and the pinion drive gear. This is easily resolved by inserting 1 or 2 of the included thin shims behind a diff outdrive ball-bearing, depending on how much play there is.
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1. FRONT & REAR DIFFERENTIALS 2x Graphite Grease (HUDY #106210) F=R IMPORTANT! Use the same diff outdrives on both ends of a diff. REAR ➌ FRONT 940816 ➋ BB 8x16x5 Graphite Grease (HUDY #106210) Graphite Grease (HUDY #106210) 964060 ➊ ➎ DETAIL Use HUDY Ball-Bearing Grease #106220 - STANDARD #106221 - BLUE #106222 - RED ➍ S 6x18x0.2 STEP ➎ DETAIL 971061 O 6x1.55 ➏ 980261 P 2.5x11.
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1. CENTER DIFFERENTIAL ➌ ➋ Graphite Grease (HUDY #106210) 940816 BB 8x16x5 ➊ STEP ➎ DETAIL Use HUDY Ball-Bearing Grease #106220 - STANDARD #106221 - BLUE #106222 - RED ➍ 964060 Graphite Grease (HUDY #106210) S 6x18x0.2 ➏ 971061 O 6x1.55 DETAIL ➎ 980261 P 2.5x11.5 VERY IMPORTANT! Use the following silicone oil included in the kit for initial setting: Center diff: 7 000cSt CORRECT 903312 INCORRECT IMPORTANT! OIL SFH M3x12 Do not overfill the differential.
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3. REAR SUSPENSION #353113 #353123 #353317 #353325 XB8’16 COMPOSITE REAR LOWER SUSPENSION ARM - RIGHT XB8’16 COMPOSITE REAR LOWER SUSPENSION ARM - LEFT XB8 ALU REAR LOWER SUSP. HOLDER - FRONT - SQUARE ADJ. ROLL CENTER XB8 ALU REAR LOWER SUSP. HOLDER - REAR - SQUARE ADJ.
3. REAR SUSPENSION MEDIUM SUSPENSION ARMS REAR SUSPENSION ARMS 353371 SHIM 4x10x2 #353115 MEDIUM OPTION #353116 HARD OPTION #353116-XH X-HARD 1° RR 0.5° 1° 1° 0.5° Do not use INNER positions. 0.5° 1° RF RF INCLUDED GRAPHITE SUSPENSION ARMS RR 0.5° 1° #353116-G GRAPHITE OPTION 901408 HARD SUSPENSION ARMS RR RF 0.5° 1° All positions are available. 0.5° All positions are available. SB M4x8 DETAIL 3.5x45mm ➍ Check for free movement RR ➌ 909372 SS 3.5x22 ➊ RR 0.
3. REAR SUSPENSION 2x Install the pivot balls with Professional Multi Tool (HUDY #183011) L=R DETAIL 1.5mm 6mm 901312 SB M3x12 901303 SB M3x3 L=R STEP ➍ DETAIL 1.5~2.0mm 901305 SB M3x5 DETAIL 3x3mm ➌ 902318 SH M3x18 3x18mm 903308 ➋ SFH M3x8 ➊ SET-UP BOOK 3x5mm 3x8mm ANTI-ROLL BAR INITIAL SETTING REAR ANTI-ROLL BARS DETAIL DETAIL DETAIL Loosen the 3x5 setscrew if the anti-roll bar does not turn freely Step ➊ Step ➊ check for free movement 14 #353418 ø1.8mm OPTION #353420 ø2.
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4. REAR SUSPENSION 2x L=R Ensure that the rear upright moves freely. If it does not move freely, use sandpaper to thin both wheelbase adjustment shims. 353370 SHIM 3x9x1 DETAIL Shims for wheelbase adjustment 353370 SHIM 3x9x2 2+1+1mm INITIAL SETTING 960030 N M3 DETAIL Do not overtighten the self-locking nut. Overtightening may result in suspension binding. ARM REAMER (HUDY #107633) Check for free movement If the rear upright does not move freely, use a HUDY Arm Reamer to resize the hole.
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5. FRONT SUSPENSION FRONT LOWER SUSP. ARMS #352120 SOFT #352120-M MEDIUM OPTION INCLUDED #352120-G GRAPHITE OPTION 909372 #902407 HEX SCREW SH M4x7 WITH HEX FROM BOTTOM (4) 352324 352314 901408 357212 353371 352314 902318 352323 909395 352120-M 901303 352470 352006 352492 333450 901305 903308 901312 FRONT ANTI-ROLL BARS 352460 352470 #333451 ALU ANTI-ROLL BAR PIVOT BALL 5.
5. FRONT SUSPENSION 353371 SHIM 4x10x2 ➍ 3.5x22mm FR 901408 SB M4x8 ➌ ➊ ➋ FR 1° INITIAL SETTING 909372 4x8mm 2mm 0.5° SS 3.5x22 ➎ INITIAL SETTING FF ➌ 3.5x45mm ➊ ➍ FF 1° DOWNSTOP SETTING DETAIL INITIAL SETTING All possible mounting alternatives of eccentric bushings DETAIL If the suspension arms do not move freely, use a HUDY Arm Reamer to resize the holes. #902407 909395 2.0mm Allen 0.0mm 0.5° SS 3.5x45 (HUDY #107634) Downstop screw for fine tuning.
5. FRONT SUSPENSION 2x L=R 1.5mm 6mm 901312 SB M3x12 Install the pivot balls with Professional Multi Tool (HUDY #183011) L=R 901303 STEP ➍ DETAIL 1.5~2.5mm SB M3x3 901305 SB M3x5 DETAIL 3x3mm ➍ 902318 ➋ SH M3x18 3x18mm ➌ 903308 SFH M3x8 ➊ 3x5mm 3x8mm DETAIL Step ➊ Loosen the 3x5 setscrew if the anti-roll bar does not turn freely FRONT ANTI-ROLL BARS SET-UP BOOK ANTI-ROLL BAR 20 #352487 1.6mm OPTION #352489 1.8mm OPTION #352490 2.0mm OPTION #352492 2.2mm INCLUDED #352493 2.
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6. FRONT SUSPENSION 2x L=R ALU pivot ball BLACK color DETAIL STEEL pivot ball SILVER color #357253 Brass Adjusting Nut M15x1 Tighten hex nuts using HUDY tool #107581 2x PIVOT BALLS MUST MOVE FREELY During initial assembly, tighten each hex nut until the pivot ball starts to bind, then loosen slightly. Verify that the pivot balls move freely. L=R 357256 SHIM 6x13x1 1mm m 2.5m HUDY Tool Allen 2.5mm FRONT UPPER SUSP.
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6. FRONT & REAR ASSEMBLY Push the top of the holder with fingers together to insert the brace with body post. 902335 SH M3x35 960030 N M3 #353280 GRAPHITE BRACE SET for extra stiffness adjustment.
7. STEERING #351348 GRAPHITE UPPER PLATE 351301 #352658 BALL STUD 6.8mm WITH BACKSTOP L=6mm - M3x8 (2) 903312 903310 903312 903308 902312 351344 NOTE Must be used also 2pcs of #303136 shim 3x7x1mm.
7. STEERING 970121 DETAIL O 12.1x1.6 INITIAL PRELOAD SETTING 4~5mm DETAIL SET-UP BOOK SERVO SAVER 3.0mm HUDY Tool Allen 3.
7. STEERING 902310 SH M3x10 All possible mounting alternatives of eccentric bushings 903308 SFH M3x8 DETAIL 0.5° 1° SET-UP BOOK NOTE ORIENTATION INITIAL SETTING ROLL CENTER 3x12mm 3x12mm 3x12mm 3x10mm DO NOT OVERTIGHTEN SCREWS DETAIL 902312 SH M3x12 M3 903310 SFH M3x10 M4 Check for free movement NOTE ORIENTATION DETAIL 903312 SFH M3x12 After the top deck assembly check for free movement of steering system.
7. STEERING 908312 SCH M3x12 NOTE ORIENTATION 1.0mm 1.0mm 2.0mm INITIAL SETTING 1° 0.5° #352051 XB8 GRAPHITE FRONT SHOCK TOWER 4MM All possible mounting alternatives of eccentric bushings UPPER CLIP Behind arm CASTE R F=R CASTER UPPER CLIP LOWER SHIM (Behind arm) (Behind arm) 4mm 2mm SET-UP BOOK ROLL CENTER CASTER 2x 4mm 24º 21º 3mm 25.5º 22.5º 2mm 27º 24º 1mm 28.5º 25.
8. CENTER DIFF & BRAKE #354057 GRAPHITE CENTER DIFF MOUNTING PLATE #354113 SUPER-LIGHTWEIGHT VENTILATED BRAKE DISK PRECISION-GROUND (2) 902330 Must be used for 47T and 48T spur gear.
8. CENTER DIFF & BRAKE STEEL 2x FIBRE FIBRE 2x STEEL OVAL HOLE CA NOTE ORIENTATION CA ROUND HOLE Roughen steel plates with sandpaper before gluing fibre pads 2x #354131 GLUED BRAKE PADS SET-ULTRA EFFICIENT (4) F=R ROUND HOLE NOTE ORIENTATION 902316 OVAL HOLE NOTE ORIENTATION SH M3x16 For improved brake efficiency and increased lifespan use the OPTION brake bads with springs.
8. CENTER DIFF & BRAKE NOTE ORIENTATION 903308 SFH M3x8 NOTE ORIENTATION OF ALL PARTS 3x8mm 903412 SFH M4x12 4x12mm NOTE ORIENTATION OF ALL PARTS All screws 902330 SH M3x30 Before inserting 3x30 long screws, loosen the four flat-head screws in the upper plate by 1/2 turn (CCW). Tighten all screws after assembly.
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9. FUEL TANK & ENGINE Threadlock on all screws 902305 SH M3x5 961032 S 3.2 Threadlock on all screws All screws 908312 SCH M3x12 IMPORTANT! 7x10x0.2 / 0.3 / 0.5 Use appropriate shims to achieve proper clutchbell endplay 964073 S 7x10x0.2 Use the cone included with your engine, or use OPTION XRAY cone #358540 964074 S 7x10x0.3 964075 S 7x10x0.5 When installing the engine, first check that the drive shaft does not touch the engine.
9. FUEL TANK & ENGINE Hold the flywheel using HUDY Flywheel Tool #182015 Note the orientation of the clutch shoes. The short side of spring must be in the groove of the flywheel nut. 359050 BB 5x10x4 Tighten the clutch nut using HUDY tool #107581 908308 SCH M3x8 961032 S 3.2 These bearings must still be regularly serviced and replaced when worn out. 10~ CLUTCHBELLS 10.
9. FUEL TANK & ENGINE 3x16mm DETAIL 902316 SH M3x16 2.2x6mm 903310 SFH M3x10 906206 SFP 2.
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10. RADIO CASE Servo screw (NOT INCULDED) step 1 Plug the connectors into the receiver in Step 2 902314 SH M3x14 NOTE NOTE ORIENTATION Use the shims only if the servo is too high and extends from the case step 2 Use foam to cushion the inside of the radio case so the receiver and battery cannot vibrate or move.
11. SHOCK ABSORBERS 358041 358055 PISTONS 358043 10 holes/ø1.1mm 8 holes/ø1.2mm 358043 8 holes/ø1.3mm 960026 358040 6 holes/ø1.2mm 6 holes/ø1.4mm 358264 358087-S 358225 358032 358033 358165 6 holes/ø1.3mm DETAIL 970100 358019 358124 970180 971034 358074 358142 358335 358150 358020 #358265 REAR SHOCK SHAFT 71.5mm (2) 358315 352460 #358027 PISTON 5-HOLE (1.5mm) & 2-HOLE (1.0mm) (4) #358028 PISTON 6-HOLE (1.3mm) & 2-HOLE (1.1mm) (4) #308029 PISTON 6-HOLE (1.4mm) & 2-HOLE (1.
11. SHOCK ABSORBERS DETAIL 358040 6 holes ø1.3mm pistons S 2.5x6x0.5 960026 6 holes ø1.3mm pistons SHORT rod N M2.5 Install the piston with Professional Multi Tool (HUDY #183011) LONG rod NOTE ORIENTATION BAG BAG 11.1 FRONT SHOCK REAR SHOCK #358027 PISTON 5-HOLE (1.5mm) & 2-HOLE (1.0mm) (4) #358028 PISTON 6-HOLE (1.3mm) & 2-HOLE (1.1mm) (4) #308029 PISTON 6-HOLE (1.4mm) & 2-HOLE (1.1mm) (4) #358030 PISTON 8-HOLE (1.2mm) & 2-HOLE (1.2mm) (4) #358031 PISTON 8-HOLE (1.3mm) & 2-HOLE (1.
11. SHOCK ABSORBERS 2x FRONT SHOCKS 2x REAR SHOCKS DETAIL 970180 O 18x1.8 2x FRONT SHOCKS DETAIL 2x REAR SHOCKS Professional Multi Tool (HUDY #183011) 1 mm DETAIL DEFAULT SHOCK REBOUND SETTING 0% (LOW REBOUND) FRONT (SHORT) 2x Oil 450cSt 2x REAR (LONG) Oil 350cSt Follow the steps below to set the shock rebound to the default setting of 0%. SET-UP BOOK HALF TIGHTEN 50% SHOCK OIL TIGHTEN FULLY 100% DETAIL 3~5x UP & DOWN 40 ➊ ➋ ➌ ➍ ➎ ➏ ➐ Extend the shock shaft completely.
11. SHOCK ABSORBERS FRONT shock PRELOAD DETAIL 2x REAR SHOCKS 2x FRONT SHOCKS approx. 2mm SHORT front shock LONG rear shock REAR shock PRELOAD SHORT spring LONG spring IMPORTANT! approx. 2mm SET-UP BOOK SPRING RATE SHOCK PRELOAD RIDE HEIGHT IMPORTANT! Both front shocks must be the same overall length. IMPORTANT! Both rear shocks must be the same overall length. FRONT & REAR SHOCKS ALTERNATE SHOCK REBOUND SETTING (50% AND 100%) The default shock rebound setting is 0% (as described on page 40).
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12. FINAL ASSEMBLY SILICONE TUBING 901303 8mm SB M3x3 961022 S 2.2 Servo screw (NOT INCLUDED) Ensure that the servo is in neutral position before attaching the servo horn ➊ Remove the screws from mounting plate and servo horn NOTE ORIENTATION 303125 SHIM 3x6x3 ➋ Install the servo brace ➌ Check free move 8mm THREAD 8mm THREAD NOTE ORIENTATION CONICAL SHIM 3x6x2mm 10mm THREAD 3x6x3mm 362280 10mm THREAD CON. SHIM 3x6x2 6.
12. FINAL ASSEMBLY 902308 #358832 AIR FILTER RAIN COVER SH M3x8 Apply #106240 HUDY air filter oil and follow the engine instructions to service the air filter. Cut the silicone tube depending on engine and muffler. Use the plastic clips to hold the tubes together. SILICONE TUBE MARKED AS BLUE = FROM FUEL TANK TO CARBURETOR SILICONE TUBE MARKED AS RED = FROM MUFFLER TO FUEL TANK (TOP) Keep fuel line away from clutchbell and flywheel.
13. FRONT C-HUB SUSPENSION 352160 901303 902325 352580 352151 303128-K 352287 902316 352621 960030 352151 353170 960030 901408 352652 903308 352180 352277 352121-H 352378 902412 357230 352293 902305 352170 902316 352245 352293 ECCENTRIC BUSHINGS #352170 0° - STEEL INCLUDED #352171 1° - STEEL OPTION 902412 BAG 13 303128-K ALU SHIM 3x6x6.0MM - BLACK (10) 352121-H COMPOSITE FRONT LOWER SUSPENSION ARM - HARD 352151 FRONT UPPER ARM BALL JOINT (2) - V2 352160 STEEL MOUNTING BALL 6.
13. FRONT C-HUB SUSPENSION 2x Follow the TECH TIP on page 5 for drive shaft pin servicing L=R NOTE ORIENTATION OIL 940816 BB 8x16x5 980317 P 3x17 To tighten the setscrew you can also use the HUDY 17mm Wheel Nut Tool #107570 Use HUDY Ball-Bearing Grease for servicing: 901504 SB M5x4 #106220 - Standard #106221 - Extra #106222 - Premium 903308 SFH M3x8 2x L=R m 2.
13. FRONT C-HUB SUSPENSION DETAIL L=R 17.5mm 909395 SS 3.5x45 908312 SCH M3x12 INITIAL SETTING 1° 0.5° L=R STEP ➍ DETAIL 1.5~2.
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MAINTENANCE ENGINE OPERATION PREPARING TO OPERATE THE ENGINE • Never modify the engine or muffler. • Confirm the position of needle and idling before running. Be sure to run a new engine smoothly. • Make sure the air filter is clean and oiled. • Never run your engine without an air filter. Your engine can be seriously damaged if dirt and debris get inside the engine. • For proper engine break-in, please refer to the manual that came with the engine.
THROTTLE LINKAGE ADJUSTMENT NEUTRAL (IDLE) ADJUST INDIVIDUAL LINKAGES SEPARATELY TO AVOID INTERFERING WITH THE OPERATION OF THE OTHERS 0.5mm ENGINE IDLING ~1mm IDLING ADJUSTMENT SCREW. Use to adjust the idle setting of the carburetor. Do not allow carburetor to close to less than 1mm. • Turn on the transmitter and receiver and set the engine control servo trim to the neutral position. • Adjust the idle adjustment screw on the carburetor to open approx. 1mm.
RC AMERICA, 2030 Century Center Blvd #15, Irving, TX 75062, USA PHONE: 214-744-2400, FAX: 214-744-2401, xray@rcamerica.
