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Summary of Contents for Yamaha XS750

  • Page 2 SPEC I FICAT IONS GENERAL SPECIFICATIONS Crystal Silver Basic color Dimensions: 2180mm (85.8 in.) Overall length 835mm (32.9 in.) Overal I width 1150mm (45.3 in.) Overall height 810mm (31.9 in.) Seat height 1465mm (57.7 in.) Wheelbase 145mm (5.7 in.) Minimum ground clearance 27°...
  • Page 3 Transmission: Constant mesh, 5-speed, drum shifter Teeth, ratio, overall 32/13 2.461 13.285 27/17 1.588 8.636 26/20 1.300 7.069 1.095 5.955 22/23 0.956 5.201 Secondary Drive: Shaft drive Transmission utput Type, teeth, ratio Spur gear, 34/32, 1.063 Middle gear case Type, teeth, ratio Bevel gear, 19/18, 1.056 Final gear case Type, teeth, ratio...
  • Page 4 Middle gear capacity: 375cc 13 oz.) case Final Gear case capacity 300cc ( 1 00 oz.) Recommended I u b r i can If temperature does not go below SAE 90 Hypoid oil, G L-4 gear 5°C (40°F) If temperature does not go above 15°C (60°F) SAE 80 Hypoid gear oil, GL-4 A I I weather...
  • Page 5 rance 0.1 6~ 0.20m m (Cold engine) "A" head diameter face width 2.26 ± 0.57mm "B" "C" seat width 1.3 ±0.15mm "D" margin thickness 1.2 ± 0.2mm .010mm Stem diameter (O.D.) -.025mm .019mm Guide diameter (I.D.) "B" -.010mm Stem-to-guide clearance 0.020~0.041mm EXHAUST CI ea rance...
  • Page 6 Crankshaft and Connecting Rods: Main bearing oil clearance 0.022~0.044mm (.0009~.0017 in.) 0.032~0.054mm (.0013~.0021 in.) Rod bearing oil clearance Main journal run-out (maximun) 0.03mm (.0012 in.) Oil Pump Housing-to-outer rotor clearance ,090~.015mm (.0035~.0059 in.) Outer rotor-to-inner rotor clearance .03 ~.09mm (.0011~.0035 in.) Clutch 3.0mm (0.12 in.) Friction plate thickness standard...
  • Page 7 Chassis Wheels and Tires Rim run-out, vertical 2.0mm (.080 in.) Rim run-out, horizontal l.0mm (.040 in.) Tire pressure, front, normal riding (26 p.s.i.) High speed or with passenger 2.0 kg/cm2 (28 p.s.i.) Tire pressure, rear, normal riding 2.0 kg/cm2 (28 p.s.i.) High speed or with passenger 2.3 kg/cm2 (33 p.s.i.) Brakes...
  • Page 8 ~ ~~ Mitsuba SM-224C Starter motor type Armature coil resistance (2O°C) 0.007 ohms 0.01 ohms Field coil resistance (2O°C) 12.5mm (0.5 in) Brush length standard minimum 5.5mm (0.22 in) Brush spring pressure 620 ± 60g (22.0 ± 2.0 oz) Armature mica undercut 0.5 ~ 0.8mm (0.02 ~ 0.03 in) Yuasa YB 14L...
  • Page 9 C. Torque Specifications Engine 1.5 ~ 2.5 m-kg (11.0 ~18.0 ft-lbs.) Spark plug Cam cap nut 0.8 ~ 1 m-kg (6.0 ~ 7.0 ft-lbs.) 3.8 m-kg (27 ft-lbs.) Rod cap Starter clutch bolt 2.8 ~ 3.2 m-kg (20 ~ 23 ft-lbs.) 1.3 ~ 2.1 m-kg (9 ~ 15 ft-lbs.) Shift cam locating bolt Detent assembly...
  • Page 10 Components should be room temperature. 500 - 600...
  • Page 11 SPECIAL TOOLS Final drive gear holding t o o l Valve guide remover Clutch holding t o o l Valve guide installer Clutch plate installation t o o l Middle and final gear holding t o o l Valve spring compressor Damper special tool Clutch lock nut wrench Cam chain cutter...
  • Page 13 d. Turn petcocks to "prime" position. a. The engine must be warmed up before setting idle speed. e. Start motorcycle and allow it t o warm up for minutes. The warm-up is complete when b. Set engine idle speed by turning the throttle engine responds normally t o threttle opening.
  • Page 14 C. Engine/Transmission Oil b. Pull out the element. Oil level measurement a. T o check the level, warm the engine up for several minutes. Stop the engine. With the engine stopped, screw the dip stick completely out and then rest the stick in the hole. Cleaning method a.
  • Page 15 d. Remove the oil filter bolt and filter element. h. After replacement of engine oil, and/or oil filter, be sure t o check the oil pressure and oil leakage. The oil pressure indicator lightshould go of f afte r the engine started.
  • Page 16 d. Fill the gear case(s) up to specified level. Take care not to allow foreign CAUTION: Oil Capacity: material t o enter the middle and/or final 375cc (12.7 Middle gear case: U S . aear case. 300cc (10.0 Final gear case: U.S.
  • Page 17 1. Remove the breaker cover 2. Remove the cam chain tensioner cover. 2. Mechanism adjustment The second adjustment is located behind the adjusting cover. Removing the cover will expose the adjusting set screw and lock nut. Loosen the lock nut and rotate the set screw in until it lightly seats against a clutch push rod that works with the set screw to operate the clutch.
  • Page 18 Reinstall the chain tensioner cap and the con- Exhaust valve clearance (cold) tact breaker cover. 0.21 - 0.25mm (.008 -.010") Intake valve clearance (cold) 0.16 - 0.20mm (.006 - ,008") Valve Clearance Adjustment Valve clearance must be measured with NOTE: the engine a t room temperature.
  • Page 19 EXAMPL E: Exhaust valve, installed pad: NOTE: The tappet adjusting tool is fastened No. 250 (read down) to the cylinder head using one ( 1 ) allen screw Measured clearance: 0.32mm such as one used t o install the cylinder head (read across) cover.
  • Page 20 Intake . . . CLEARANCE Exhaust...
  • Page 21 5. Turn over engine with kick or electric Remove the drain cover and clean it with starter (make sure battery is fully charged) with solvent. throttle wide open until pressure indicated on the gauge does not increase further. Standard: I 0 k g / c m ! (142 psi) Minimum: 9kg/cm! (128 psi) Maximum: 11kg /cm! (156 psi)
  • Page 22 1) Loosen the adjusting screw lock nut. Brake pad check To check pad wear, open the wear indicator By turning the adjusting screw in or out, cap. If any pad is worn t o the red line, replace adjust the play of the brake lever and then both pads in the caliper.
  • Page 23 c. Be careful that water or other contamination 2. Front axle does not enter the master cylinder when re- filling. Water will significantly lower the a. Check axle nuts. boiling point and may result in vapor lock. Front axle nut torque: 7.0~10.0 m-kg (50~72 ft-lb) Rear axle nut torque:...
  • Page 24 Inspect drain screw gasket. Replace ifdamaged. Reinstall drain screw. Pour specified amount of oil into the fork inner tube. Front fork oil (each fork): 170cc 2OW Yamaha Fork Oil After filling, slowly pump the outer tubes up and down to distribute the oil.
  • Page 25 3. If there is looseness i nthe steering head, loosen Contact Breaker Gap: the crown pinch bolt and steering fitting bolt. 0.4mm (.012~.016 in.) 4. Use steering nut wrench to loosen top steering fitting nut. The top nut serves as a lock nut. 5.
  • Page 26 The above procedure i s recommended for set- ting ignition timing. However, the following information i s provided so that the position of the static pointer can be verified using a degree wheel. There are also three (3) pair of unmarked Retarded ignition: 10°...
  • Page 27 b. Adjust vertically as follows: The spark plug must be removed and checked. Check electrode wear, insulator color, and electrode gap. 1) Loosen adjusting screw under headlight body. Spark plug gap: 0.6~0.7mm (0.02~0.03 in.) Engine heat and combustion chamber deposits will cause any spark plug t o slowly break down and erode.
  • Page 28 the "on" position unless the engine oper- ating). Disconnect fuel pipes and vacuum pipes ENGINE OVERHAUL from petcock. L i f t seat and remove fuel tank holding bolt. 3 - 1 ENGINE R EMO VAL Remove fuel tank. NOTE: It is n ot necessary t o remove the engine t o remove the cylinder head, cylinder, or pistons.
  • Page 29 Side Cover, Air Cleaner Case Remove bolts holding air cleaner case to frame. Note ground wire connection on left Remove left and right side covers. frame bracket. DOHC Pull air cleaner case t o the rear. Remove clutch cable from holder attached t o the left carbu- retor.
  • Page 30 F. Drive Shaft Joint Remove spark plug wires and tachometer cable. 1. Pull rubber boot from drive shaft coupling t o expose four (4) bolts. Remove t w o ( 2 ) screws holding starter moto r cover. Remove starter moto r cover. Disconnect electric starter cable.
  • Page 31 2. Remove points cover. Rotate the crankshaft 5. Remove the cam caps t o T.D.C. o f the compression stroke o n the NO. 1 (L.H.) cylinder. Tie each end of the cam CAUTION: To avoid damage to the camshaft chain t o prevent it fr o m falling in to the crank- caps, observe the following: cases when it i s separated.
  • Page 32 Remove spark plugs. Remove cylinder head holding nuts and bolts as follows: a. Loosen each n u t and b o l t # t u r n , observing the torque sequence. b. Remove the cylinder head holding nuts first.
  • Page 33 C. Piston Removal 4. Remove the bolt, plate washer and lock washer from the rotor. Use the rotor holding tool and 1. Mark each piston t o aid in reassembly. bolt (special tools) t o remove rotor. 2. Place a clean towel or rag into the crankcase t o keep circlips and material from falling into the engine.
  • Page 34 4. Remove primary driven gear and chain. F. Clutch and Primary Driven Gear 1. Remove small circlip and washer from R.H. end of transmission. Remove clutch housing. Remove larger circlip. NOTE: If the clutch plates are stuck to the housing, thread in the clutch adjuster screw on the left side of the engine.
  • Page 35 Remove pressure plate screws and clutch G. Kick Gear Removal springs. Remove pressure plate. Remove circlip holding the kick idlegear. 8. Remove clutch plates, clutch push rod and ball bearing. Install the kick crank on the kick shaft. Pull the kick starter assembly and the kick idle gear o u t together.
  • Page 36 4. Remove kick gear holder bolts. Use a slide H. Shift Lever, Shift Shaft Removal hammer to remove the holder. 1. Remove clip holding shift lever two (2). Re- move the lever. 2. Remove clip holding shift shaft lever. Remove shift shaft.
  • Page 37 Remove neutral light wire. Remove breaker assembly wiring harness from clamps on crank- case. Remove three (3) breaker plate holding screws and remove breaker assembly. Remove governor assembly. Remove starter clutch assembly Electric Starter Removal Remove L.H. crankcase cover. 2. Remove idler gear 1 and shaft. 5.
  • Page 38 6. Remove cam chain dampers. Middle Gear Case Disassembly is covered in the Shaft 102. Drive, Section page L. Transmission Bearing Housing Removal 7. Remove two (2) starter motor securing bolts. Remove starter motor. Remove the transmission bearing housing bolts. Re- move housing.
  • Page 39 Remove oil pump cover and rotor assembly. N. Oil Pump Removal and Disassembly 1. Remove strainer cover. 5. Remove pressure relief valve: remove circlip, washer, spring, and plunger. Remove oil pump check valve: remove cir- clip, plug, spring, and plunger. 2.
  • Page 40 1. Loosen each bolt turn, starting with the 2. Remove shift fork guide bar circlip (E-clip). unnumbered bolt. Continue by loosening the Remove guide bar. highest numbered bolts first. The numbers of the bolts are cast in the cases. Numbers 24~ 15 are on the top case.
  • Page 41 Remove bolt holding middle drive gear t o drive axle. Remove spacer. Remove shift cam detent and shaft cam se- Loosen transmission bearing cap nuts # turn. curing bolt. Remove nuts and cap. Remove circlip on shift cam stopper plate. Remove stopper plate and shift cam.
  • Page 42 AXLE, main (13T) WASHER, plate (30.2-40-2.0) WASHER, spring GEAR, 4th pinion (21T) CIRCLIP BOLT, hexagon socket head G EA R 4th wheel (23T) CIRCLIP MIDDLE DRIVEN GEAR SHIM WASHER, gear hold 5 COMP. (34T) GEAR, 3rd wheel (26T) (25.2-30-1 .O) COLLAR (35-40-16) GEAR, 5th wheel (22T) GEAR, 3rd pinion (20T)
  • Page 43 CAM, shift SPRING, compression B A R , shift fork guide 2 PIN, dowel (4-8) G ASKET, drain plug F OR K, shift 1 PIN, dowel (4-17.8) 13 SCREW SHAF T , shift lever B E A R I N G B O L T SCREW, flat head C l R C L l P ( 3 4 ø...
  • Page 44 3-3 INSPECTION AND REPAIR 0.10 mm Intake .020-.041mm A. Cylinder Head Cover (.004") (.0008~.0016") Place head cover o n a surface plate. There should be Exhaust .035-.059mm 0.12mm warpage. Correct b y re-surfacing as follows: (.0014~.0023") (.005") Place #400 o r #600 grit w et sandpaper o n surface 2.
  • Page 45 d. Af te r installing t h e valve guide, use 7mm s t il l exist, then continue to c u t w i t h the pits reamer (special to o l) t o obtain the proper valve 45°...
  • Page 46 seat have been re-surfaced and now require measure spring free length. I f the free length final light grinding operation for perfect seal- of any spring has decreased more than 2mm (.080") ing. from i t s specification, replace b. Apply a small amount of coarse lapping com- pound t o valve face.
  • Page 47 2. Valve lifter PLASTIGAUGE a. Check each valve lifte r for scratches or other damage. I f the lifter i s damaged any way, the cylinder head surface which rides is probably also damaged. I f the damage is severe, may be necessary replace both the lifter and the cylinder head.
  • Page 48 or disintegrating damping rubber will contam- Cylinder wear should be measured a t three inate the engine oil and will lead to excessive depths with cylinder bore gauge. (See illu- engine noise. stration.) Standard Wear Limit Cam Chain Dampers 68.00~68.02mm 68.10mm Cylinder bore (2.677~2.678 in.)
  • Page 49 The color mark is painted on the expander spacer. Standard 67.96mm Size Color 67.97 Oversize 1 Oversize 1 Brown 68.25mm Oversize 2 Oversize 2 68.50mm Oversize 3 Oversize 3 Black 68.75mm Oversize 4 Yellow c. Push the ring into the bore and check end gap clearance with feeler gauge.
  • Page 50 Run-out limit: .03mm (.001 in.) If run-out exceeds limit, replace crank. 2. Inspection Of Inserts LEFT CENTER Check the bearing inserts. If the inner orouter surface is burned, flaked, rough, scratched or worn, the insert should be replaced. Measuring Main Bearing Oil Clearance a.
  • Page 51 c. Remove connecting rod and cap. Measure There is a special thrust bearing NOTE: width of Plastigauget o determine oil clearance. (insert) located in the No. main bearing housing in the upper crankcase. The function of this insert is t o provide a bearing surface Oil clearance (rod): for crankshaft side thrust.
  • Page 52 EXAMPLE: a conventional motorcycle drive chain. The plates of the chain form a mating surface for the primary gear teeth. That is, the primary INSERT COLOR CODE gears actually mesh with the chain plates. This Blue chain is extremely durable and, under normal No.
  • Page 53 Galling on clutch plate splines will NOTE: cause erratic clutch operation. Friction and Clutch Plates Check clutch steel plates and friction plates for heat damage. Measure friction plate thick- ness at or 4 points. Measure clutch plates for warpage with dial gauge and stand.
  • Page 54 b. Kick Clip Spring Check shift cam dowel pins and side plate for looseness, damage or wear. Replace as required. 1) The kick clip is fitted to kick gear (5) and slides i n the groove. A too-tight or loose- Check the shift cam stopper plate and circlip and stopper for wear.
  • Page 55 Middle gear case lash: 0.1~0.2mm (.004~.008") If lash is not within tolerance, refer to Drive Shaft Section page 102 ENGINE ASSEMBLY AND ADJUSTMENT NOTES: 1) All gaskets and seals should be replaced when an engine is overhauled. All gasket surfaces must be cleaned.
  • Page 56 5. Install main shaft and clutch push rod seal. 6. Install shift fork guide bar and shift fork 1. Install bearing cap, washers, dnd nuts. Tighten Install circlips (E-clips). bearing cap. 7. Install middle driven gear. Make sure circlip Bearing cap torque: halves are properly installed.
  • Page 57 2. Install oil pump. Make sure rotor housing seal NOTE: When a new seal is installed, grease is positioned correctly. the lips of the seal before installation. Inspect the seal after installation. C. Crankshaft and Crankcases 1. Install crankshaft into bottom crankcase. Crankcase bearings must be well oiled.
  • Page 58 CRANK, kick 1 (40.3-54-0.8) SHIM, kick shaft COVER, kick lever BEARING BOSS, kick crank KICK ID L E GEAR ASS'Y (38/30T) BOLT SHIM, kick shaft 2 (35.3-54-0.8) WASHER, plate (15.5-24-1.5) CIRCLIP (S-35) CIRCLIP (E-10) CIRCLIP (S-17) B A L L (7/32 inch) SH IM SPRING, compression GEAR, kick 4 (20T)
  • Page 59 WASHER, plate (25.2-39-1.0) PLATE, clutch 1 DAMPER ASS'Y SPACER CLUTCH BOSS ASS'Y CIRCLIP B A L L (5/16 inch) PLATE, seat WASHER, plate (76-95-0.8) ROD, push SPRING, clutch boss BEARING OIL SEAL (SD-8-25-8) PLATE, clutch 2 WASHER, plate (69-95-5.4) BALL SCREW ASS'Y CIRCLIP SPRING, damper SCREW, adjusting...
  • Page 60 2. Install shift lever 2. The dot on shift lever 2 4. Install shim and bearing onto idler shaft. Oil must align with the dot on the shaft. the bearing. 3. Shift transmission into second gear. The line on the shift cam must align with the line on shift lever 2.
  • Page 61 next dot on the clutch boss. Follow this pat- Clutch nut torque: tern clockwise around the clutch boss until 8m-kg ft-lbs) al l friction and steel clutch plates are installed. Install push rod 1 intotheslot in the main axle. 4. Install plate washer onto main axle. Install pressure plate with the arrows matching the arrows on the clutch boss.
  • Page 62 8. Carefully install spacer and clutch housing. Use Rotor bolt torque: care t o avoid damaging friction plates. 3.0~4.0 m-kg (22~29 ft-lbs) 9. Place drive chain on drive gear. Install damper Install generator assembly. Connect oil pres- assembly into primary driven gear and install sure warning wire to the switch.
  • Page 63 K. Drive Axle Bearing Housing 1. Oil drive axle bearing. 2. Install drive axle shim on drive axle. Oil the o-ring on the bearing housing. Install bearing housing. Attach wire harness clamp to lower securing screw. Install cam chain dampers. Install the damper with the three (3) raised blocks t o the front.
  • Page 64 6. Install starter motor Crankshaft turning nut (bolt) torque: Install starter motor idler gear and kick idler 1.5~2.9 m-kg (11~21 ft-lb) gear. Install the idler gear shaft. 8 . Install clutch ball bearing and clutch push rod. N. Pistons and Cylinder 1.
  • Page 65 Position piston rings as shown. Stage l0mm nut (No.1-8): 1.5 m-kg ft-lbs) ( 1 1 OIL RING bolt (No. 9, 10): 1 m-kg (7 ft-lbs) (LOWER RAIL) Stage 2: 10mm nut (No. m-kg (25 ft-lbs) 1-8): 3 .5 8mm bolt (No. 2.0 m-kg ft-lbs) 9,10):...
  • Page 66 2. Place cam chain on cam sprockets. The dots on Manufacturer's marks or numbers NOTE: the cams must be aligned with the arrows on stamped on the rings are on the top side of the the No. 1 cam caps. The No. 1 cylinder must rings.
  • Page 67 3. Install oil filter. Remove oil filter filler bolt. NOTE: See sections on page 106 Fill oil filter with 0.5 lit (0.5 qt.) engine oil. Timing plate setting. ADD OI L H E R CAUTION: The filter must be filled with the specified amount of oil t o prime the oil pump of an overhauled engine.
  • Page 68 CARBURETOR ASS'Y CARBURETOR ASS'Y 1 CARBURETOR ASS'Y 2 CARBURETOR ASS'Y 3 NOZZLE, main (Y- 2) O-RING V AL V E SEAT ASS'Y (2.0 ø) WASHER, valve seat NET, filter F LO AT PIN, float GASKET, float chamber BODY, float chamber JET, pi lot (No.
  • Page 69 CAR B U R ETION 4-1 CARBURETOR A. Description The XS750D is equipped with three "constant velocity" (C V) carburetors mounted on rubber intake manifolds. Air flow through the venturi is controlled by a throttle slide (vacuum piston). The slide is raised and lowered by engine vacuum rather than a cable linked directly t o the throttle grip.
  • Page 70 6. Remove the four (4) screws holding the float 3. Inspect inlet needle valve and seat for wear or bowl cover.Remove float bowl cover. The main contamination. Replace these components as jet is located under a cover in the float bowl. a set.
  • Page 71 TANG 2. Jet needle adjustment The mid-range air/fuel supply affected by the position of the needle i n the needle jet. If it is necessary to alter the mid-range air/fuel mixture characteristics of the machine, the jet needle position may be changed. Move the jet needle up for a leaner condition toward the bottom position for a richer condition.
  • Page 72 C. Front Wheel Inspection CHASSIS Check for cracks, bends or warpage of wheels. If a wheel is deformed or cracked, it must be replaced. 5-1 FRONT WHEEL Check wheel run-out. I f deflection exceeds tolerance, check wheel bearing or replace A.
  • Page 73 D. Replacing Wheel Bearings 5-2 REAR WHEEL I f the bearings allow play in the wheel hub or if wheel A. Removal does not turn smoothly, replace the bearings as follows: 1. Place machine on center stand. 1. Clean the outside of the-wheel hub. Raise the seat.
  • Page 74 CAST WHEEL, (2.15-18) rear OIL SEAL (SO-27-52-5) TIRE, (4.00-18-4PR) rear COLLAR, shaft TUBE, (4.00-18) COVER, rear dust SPACER, COLLAR bearing PLATE, FLANGE, stopper torque spacer BEARING (B6204) SHAFT, wheel PIN, cotter BEARING (B6204RS) WASHER, plate COLLAR NUT, OIL SEAL (SD-25-47-7) shaft SPACER 10 SEAL,dust...
  • Page 75 1 DISK, rear brake 2 WASHER, lock 3 BOLT, hexagon 4 CALIPER ASS’Y, rear 5 CALIPER PAD K I T 6 BUSHING, boot 7 SLEEVE 8 BOLT, support 9 SCREW, bleed with cap 10 CALIPER SEAL K I T 11 NUT, crown 12 WASHER, spring 13 WASHER, plate...
  • Page 76 BUSHING, diaphragm PEDAL, brake BOLT, cap BOLT, hexagon BOLT, plug WASHER, spring GASKET SPRING, torsion BOOT, master cylinder SHAFT, brake pedal BOLT, hexagon JOINT WASHER, spring HOSE, rear brake WASHER, plate BOLT, union CIRCLIP (E-6) WASHER, plain ROD, brake CLAMP 1 NUT, hexagon CLAMP 2 12 SCREW...
  • Page 77 A. Caliper Pad Replacement NOTE: Do not depress the brake pedal when the wheel is o ff the machine so that the 1. I t is not necessary to disassemble the brake caliper piston is not forced out of thecylinder. fluid hoses t o replace the brake pads.
  • Page 78 MASTER CYLINDER ASS'Y, front N UT CYLINDER KIT, master BOLT, union CAP, reservoir WASHER SCREW, cap HOSE, brake 1 DIAPHRAGM, reservoir BOOT, master cylinder JOINT BUSHING, diaphragm BRACKET, master cylinder BOLT, hexagon BOLT, hexagon WASHER, spring WASHER, plate WASHER, spring LEVER, right HOSE, brake 2 SCREW...
  • Page 79 DISK, front brake WASHER, lock BOLT, hexagon F RO NT CALIPER ASS'Y, right F RO NT CALIPER ASS'Y, left CALIPER PAD K I T BUSHING, boot (with grease) SLEEVE BOLT, support SCREW, bleed with cap CALIPER SEAL K I T BOLT, hexagon WASHER, spring WASHER, plate...
  • Page 80 b. Remove brake lever and spring. Lightly grease the surface of the shim that contacts the pad. Bend each tab of the shim c. Remove brake hose. over the brake pad. The arrow on the shim must be in the turning direction of the wheel. B.
  • Page 81 6. Check for wear and deflection o f disc (front D. Brake Inspection and Repair and rear). Recommended Brake Component Replacement Schedule: ... Brake pads. .As required ..Piston seal, dust seal .Every two years .
  • Page 82 b. Install pad spring, shim (with arrow) and Brake hose torque: (all brake union bolts) tainer. The shim arrow is in the direction of wheel rotation. Install dust seal and clip. 2.3~2.8 m-kg (16~20 ft-lbs) c. Install pad spring and pads, Brake Disc Assembly d.
  • Page 83 WHEELS, TIRES, TUBES Make sure the wheel is balanced every time NOTE: the tire is replaced. (Refer t o Front Wheel Inspection.) A. Wheel Inspection Wheels should be inspected frequently. Wheel run-out and balancing is discussed in Chapter 5-1. I n addition, wheels must be carefully inspected for small cracks, 5-5 FRONT FORKS bends or warpage.
  • Page 84 SEAL, dust FRONT FORK ASS'Y HOLDER, axle FORK TUBE, outer left GASKET WASHER, plate GUIDE, cover under FORKTUBE, outer right NUT, nylon GUIDE, cover upper SEAL, spacer BOLT, hexagon socket head O ILS E AL SEAT, spring upper SCREW, drain STOPPER RING, oil seal SPRING COVER, upper left...
  • Page 85 5-6 STEERING HEAD B. Inspection A. Adjustment 1. Examine fork inner tube for scratches and (See Chapter 2-4 for Steering Head Adjustment.J straightness. If the tube is scratched severely or bent, it should be replaced. B. Removal If the lips of the oil seal are worn, or the oil 1.
  • Page 86 BOLT, hexagon socket head cap BEARING CAP, bolt BEARING HOLDER, handle upper COVER, ball race 1 HOLDER, handle under NUT, fitting WASHER CROWN, handle BUSHING, rubber WASHER, plate WASHER, plate BOLT, stem NUT, hexagon BOLT, pinch CLIP BOLT, pinch PLUG WASHER, plain GUIDE, wire NUT, crown...
  • Page 87 Support steering stem (underbracket) and re- D. Reassembly move bottom fitting nut. Grease bearings and races with wheel bearing 7. Remove bearings. grease. Install steering stem (underbracket) and bear- ings. Install bottom fitting nut. Tighten t o approx- imately 1.0~1.2 m-kg (7 ~9 ft-lbs). Do not over-tighten.
  • Page 88 REAR ARM COMP. BOLT, hexagon BEARING, tapered roller WASHER, spring REAR CUSHION ASS’Y, left OIL SEAL (SD-25-40-5) COLLAR (17-25-7) REAR CUSHION ASS’Y, right NUT, cap SHAFT, pivot WASHER NUT, pivot shaft WASHER, plate (10-25-2.0) PLUG BOLT BOOT, rubber WASHER, spring SPRING, tension SPRING, tension...
  • Page 89 3. I f the l e f t and right gaps differ by more than 2. The swing arm is mounted on tapered bearings. adjust as follows: Move the swing arm up and down as shown. the limit The swing arm should move smoothly, with- out tightness, binding or rough spots that a.
  • Page 90 NOTE: When installing new bearings, grease liberally with lithium base, waterproof wheel bearing grease. 2. Always replace grease seals when bearings are removed. Examine rubber boot for damage. Replace if damaged. 3. Remove final gear assembly and drive shaft. E. Installation Installation of the swing arm can be accomplished by reversing the removal procedure.
  • Page 91 5-10 FINAL DRIVE GEAR CABLES AND FITTINGS A. Cable Maintenance See Maintenance and Lubrication intervals NOTE: This section describes external inspection NOTE: charts. Cable maintenance i s primarily concerned only. See shaft drive section page 102 for overhaul with preventing deterioration through rust and weath- and adjustment.
  • Page 92 Place dial gauge and stand t o measuregear lash f. Use special wrench t o gently rotate gear pling from engagement to engagement. Note (movement) asshown. Gear lash the lash measurement on the dial gauge. ment from gear engagement t o gear engage- ment as the gear coupling is rotated.
  • Page 93 XS750 Power Flow Schematic...
  • Page 94 THE BASIC MECHANISM 1-1. An Introduction to the Mechanism Power i s transmitted from the crankshaft through the clutch and two transmission shafts to a third shaft, called the middle driven gear. A splined drive cam fits inside the middle driven gear and transmits power t o the driven cam, which is located the middle gear...
  • Page 95 The main service concerns of the Middle (4) Bearing Preload: The set load forcing tapered roller bearings against their races. Gear Case assembly are: (1) Gear Lash: The play between the gear In this case it is measured as the torsional resistance of the driven pinion bearings.
  • Page 96 1-2. Lubrication The maintenance of proper lubrication i s the most important consideration that can be given t o the shaft drive system by the owner or service person. Almost any significant wear or failure can usually be traced t o low lubricant level, contaminated lubricant, or the wrong choice of gear oil. See Chapter for specific gear oil recommendations and checking procedures.
  • Page 97 SPECIAL TOOLS The following special tools are necessary for complete servicing of shaft drive components. tool (final la sh gear) Gear measurement Gear lash measurement (middle gear) tool P.No.90890-01231 P.No.90890-01230 Middle and final gear holding tool Ring gear holding tool P.No.90890-01229 P.No.
  • Page 98 The following special tools are not available but can be constructed for shaft drive component disassembly and assembly: Press Tool No. 1 For final gear guide Press Tool No. final gear roller bearing and oil seal installation coller removal (see page126) page (see...
  • Page 99 ROUTINE MAINTENANCE AND INSPECTION 3-1. GEAR OIL TYPE AND QUANTITY NOTE: Middle gear and final gear oil can be checked with same level gauge, which is in the owners tool kit. Middle Gear Oil Capacity: 375 cc (13.0 U.S. fluid oz) Final Gear Oil Capacity: 300 cc (10.0 U.S.
  • Page 100 3-3. GEAR OIL REPLACEMENT NOTE: See Chapter 4 regarding the inspection of drained oil. page 110 A. Place an oil pan under the transmission for the middle gear and under the final gear case. C. Reinstall the middle and/or final drain plug(s).
  • Page 101 TROUBLESHOOTING 4-1. TROUBLESHOOTING CONDITIONS Basic conditions Possible damaged areas 1. A pronounced hesitation or "jerky" movement during acceleration, decelera A. Damage t o bearings. tion, or sustained speed. (This must be confused with engine surging or Improper gear lash; improper gear tooth contact. transmission characteries).
  • Page 102 B. Consider the following Inspection Notes: (1) During coasting, accelerating or decelerating, the “rolling rumble” will increase with rear wheel speed, not engine or transmission gear speeds. However, such noise may also be due to wheel bearings. (2) Noise that varies with acceleration and deceleration: Following incorrect reassembly, a condi- tion of too-little gear lash may produce a whine during deceleration.
  • Page 103 D. Oil Leak Inspection If a shaft drive component is suspected of leaking oil, first thoroughly clean the entire machine. The apparent location of an o il leak on a dusty machine may be misleading. Dry the machine and apply a leak-localizing compound or a dry-powder spray deodorant that will limit the flow o f any leaking oil.
  • Page 104 REMOVAL OF COMPONENTS 5-1. Removal of Components It is normally not necessary to remove the engine t o remove the Middle Gear Case. A. Drive Shaft Joint rubber boot from drive shaft Pull coupling t o expose four (4) bolts. Remove 4 coupling bolts;...
  • Page 105 5-2. Checking Gear Lash A. Check final drive gear lash as follows (1) Remove final drive gear case. (2) Temporarily secure bearing housing as 2 ): follows (Type 1 and Type Place thickness of washer (about 1/4 inch thick) over opposite bearing housing studs.
  • Page 106 (8) Check this engagement 4 positions. Rotate the shaft 90° each time and (0.004 0.008 in): repeat the lash check. gear Measured value and actual gear lash B. Check middle gear lash as follows Support gear case in a vise by the out. put shaft flange.
  • Page 107 MIDDLE GEAR 6-1. Disassembly and Inspection A. Purpose of Drive Pinion Removal By removing the drive pinion shaft only, If either the drive pinion or driven pinion the following can be inspected: gears are damaged, both must be replaced as (1) Drive Pinion Bearing (page 117 - 118) a set.
  • Page 108 Drive Pinion Assembly Inspection B. Disassembly (Initial) Check bearing movement for damage to (1) Remove bearing housing cap. balls, rough spots, bearing looseness. Inspect gear teeth. If any gear tooth is damaged, the gear set must be replaced. Driven Pinion Assembly Inspection Leave driven pinion installed.
  • Page 109 (3) Remove housing with bearing. Remove bearing from case. (2) Hold flange in a vise. Remove self- locking nut. (3) Tap driven pinion with a soft hammer. Remove pinion from bearing housing. F. Driven Pinion Disassembly (for replace- ment only) NOTE: The following driven pinion disassembly should be performed only if the bearings...
  • Page 110 6-2. Reassembly and Adjustment A. Drive Pinion Assembly (1) Install bearing into middle gear case. (2) Install bearing into bearing housing. (3) Install bearing inner race half onto drive pinion shaft. (5) Bearing housing outer race removal requires an oven. Heat bearing housing to 100°C (212°F).
  • Page 111 (6) Stake the locking collar of the nut to the slot on the drive pinion shaft. (3) When gap is adjusted properly, remove cap. Install new housing cap gasket. Reinstall cap and tighten screws to (7) Install a new o-ring on the bearing specified torque.
  • Page 112 NOTE: To increase gear lash, use a thicker The pattern should be centered in the shim. Gear lash can also be adjusted tooth drive surface. However, wear by changing the driven pinion bearing and drive forces tend to move the housing shim(s) in the same way.
  • Page 113 (6) Final assembly (2) Install the larger bearing on driven a. Install circlip on drive pinion shaft. shaft using a press and a collar of the proper size. Oil the bearing. b. Remove housing cap screws. Clean threads and apply thread sealant and reinstall.
  • Page 114 c. Hold bearing housing and check preload. This preload is determined by turning the shaft with a torque wrench and measuring the resistance of the bearings to the rotation of the shaft. CAUTION: Do not hold the bearing housing in a vise.
  • Page 115 FINAL GEAR 7-1. Disassembly and Inspection 23. Ring gear shim ,0.25.0.3. 0.35.0.4.0.45.0.5~ A. Purpose of Ring Gear Removal By removing the ring gear assembly only, the following inspections can be made. (I) Drive pinion bearings (page 117 ~118, 125) (2) Ring gear bearings (3) Gear teeth condition (4) Tooth contact pattern (page 121, 128 - 129) (5) Drive pinion bearing preload (page 128 - 128)
  • Page 116 B. Ring Gear Removal NOTE: (1) Remove the nuts (10) holding the bearing The following drive pinion disassembly housing. should be performed only if gearing re- (2) Remove the ring gear assembly and thrust placement is necessary. Do not re-use washer from final gear case.
  • Page 117 (3) Large bearing (rear): Use a universal- type bearing puller to remove inner race of large bearing from the drive pinion. 7-2. Reassembly and Adjustment A. Drive Pinion Assembly (4) Use a press and the press tool No. 1 (1) Install 2 new bearing outer races into (Special Tool) to push the guide the drive pinion bearing housing.
  • Page 118 Type 1: a. Install the gear coupling, plate washer, and self-locking nut. Do not install spacers yet. Tighten nut gradually until proper bearing preload is reached. Overtightening will damage the bearings. NOTE: This preload is determined by turning the shaft with a torque wrench and measuring the resistance of the bearings to the rotation of the shaft.
  • Page 119 gear lash as described in Sect- Type 2: Follow the same procedure Check ion 5-2. Page 114 Adjust as neces- described for the Middle Gear driven sary by the following procedure: pinion. a. Lash too large: Install one-size Type 2 Bearing Preload: smaller ring gear shim.
  • Page 120 Yamaha Bond # 4 as shown. Drive pinion Correction Procedure: Apply a small amount of Yamaha Bond # Reduce drive pinion shim 0.05 mm. b. Recheck to o th pattern. c. If necessary, repeat step "a" in 0.05 mm steps.
  • Page 121 c. If the distance "a" of the old and C. Ring Gear Assembly new bearings i n different, remove Ring gear assembly components ( 1 ) and measure the thrust shim (not the thrust washer). d. Use a new thrust shim that is thicker or thinner to correspond t o the difference between the old and new roller bearing assemblies.
  • Page 122 DRIVE SHAFT 8-2. Ball Joint inspection 8-l. Drive Shaft Inspection A. Removal Remove middle gear and final gear cases. A. Removal Remove drive shaft. The ball joint can See page 113, Section 5-1D for drive be easily removed from the swing shaft removal.
  • Page 123 6-1 ELECTRIC STARTING SYSTEM A. Starter Motor 1. Circuit diagram. RELAY SWITCH STARTER BATTERY STARTER SWITCH (see Section 3-2, Engine Disas- Removal sembly). Inspection and repair a. Check the outer surface of the commutator. If i t s surface is dirty, clean with No. 600 grit sand paper.
  • Page 124 5.5mm (0.22 Minimum brush lenoth: in.) f. Check brush spring pressure. Replace spring if is weak. M A I N B. Starter Relay Switch A C GEN ER A TOR 1. Inspection a. Disconnect starter relay leads a t the relay. R EGU LATOR b.
  • Page 125 2. Resistance test of field coil and stator coil. Check the resistance between terminals. If re- RECTIFIER sistance is out of specification, coil is broken. Check the coil connections. I f the coil connec- tions are good, then the coil is broken inside and it should be replaced.
  • Page 126 This is the adjusting screw. D. Checking Silicon Rectifier 1. Check silicon rectifier as specified using the Yamaha Pocket Tester. white d. Before starting engine, disconnect wire con- nector (coupler) containing 5 wires from rectifier (1 red, 1 black, white).
  • Page 127 Even if only one element is broken, replace Battery 1 2V 14AH assembly. Specific gravity: 1.28 Electrolyte Quantity: 81Occ CAUTION: The silicon rectifier can be 1.4 amp for hours Initial charging damaged if subjected t o overcharging. Special current (new battery) care should be taken t o avoid a short circuit and/or incorrect connection of the positive and negative leads a t the battery.
  • Page 128 b. Check the operation of the point cam on the D. Ignition Coil shaft. I t must rotate smoothly. 1. Coil spark gap test. Remove fuel tank and disconnect ignition coil from wire harness and spark plug. b. Connect Electro Tester as shown. IGNITION COIL, ‘ORANGE c.
  • Page 129 able ones determined by the color and condition of Standard values: the bad plugs. One machine may be ridden only in Primary coil resistance: urban areas a t low speeds; another may be ridden for 4.0 ohms ± 10% at 20°C (68°F) hours a t high speed.
  • Page 130 2)Check for 12V on brown wire t o flasher 6-2 Charging System, for checks o f battery and relay. charging system. Also check fuse condition. Re- place any "open" fuses. There are individual fuses 3) Replace flasher relay. for various circuits (see complete Circuit Diagram). 4) Replace flasher switch.
  • Page 131 I f the signal operates normally in L, R C. Self-Canceling Flasher System OFF, the following are in good condition: 1. Description: 1) Flasher unit. 2) Bulb. The self-canceling flasher system turns off the 3) Lighting circuit. signal after a period of time or distance turn 4) Handle switch light circuit.
  • Page 132 HEADLIGHT INDICATOR LIGHT DOES NOT DOES NOT FUNCTION LIGHT WHEN LOW BEAM COMES ON-HIGH BEAM IS Reserve Unit Indicator Light and/or Wiring is Defective NOT FUNCTION "HEAD" INDICATOR BULB DOES NOT GLOW Voltage on "LG" Wire to Reserve Headlight Ground...
  • Page 135 B. Selection of Driven Pinion Shim Note the number scribed on the middle CASE EXCHANGE gear cases. Proceed in above steps Page 122, Section 6-2. E). When the exterior of the middle gear or final gear case is damaged and must be replaced, pay attention to the numbers scribed on the replacement cases.
  • Page 137 Interchangeability of Parts for Type 1 and Type 2 All the parts except the following parts are interchangeable for both Type 1 and Type 2. These items can be used, however, on both Type 1 and Type 2 provided they are used for replacement in a set.
  • Page 138 O I L S C A V E N G E ( R et u r n )
  • Page 139 Note: This section only covers those points which are 750 D. different from the XS If the subject does not appear in this section, please refer to the Contents page. SPECIFICATIONS (XS750-2D Only) A. GENERAL SPECIFICATIONS Dimensions: Overall length 2,160 mm (85.0 in) Overall width 895 mm (35.2 in)
  • Page 140 Air filter: Dry foam rubber Type Ignition: Battery/coil Type NGK BP-7ES or CHAMPION N-7Y Spark plug Charging: Three-phase, regulated alternator Type Manufacture, I.D. No. Hitachi LD120-02 Maximum output 14.5 V/18A 12V 14A-Hr. Battery type Battery dimensions 134 x 166 x 89 mm National RD1143.
  • Page 141 M A IN T E N A N C E SPECIFICATIONS Engine Engine/Transmission oil capacity 3,800 cc (4.0 US qt) Total amount 3,500 cc (3.7 qt ) Oil and filter change 3,000 cc (3.2 US q t ) Oil change 2.
  • Page 143 Page numbers shown in brackets correspond to page numbers of the XS750D Service Manual. (PAGE 19 Maintenance Intervals For New Machines (XS750D, XS750-2D) Initial 1,600km (1,000miles): Initial 400Km (250miles): filter cleaning Cam chain adjustment Brake system inspection Spark plug inspection...
  • Page 144 Lubrication Intervals For New Machines (XS750D, XS750-2D) Initial 3,200km (2,000miles): Initial 400km (250miles): Replace engine/transmission oil Replace engine/transmission oil (2,400km or 1,500miles) Replace oil filter Lubricate control/meter cables Replace middle/final(rear)gear oil Lubricate throttle grip/housing Lubricate throttle griplhousing Check brake fluid...
  • Page 145 Torque Specifications Engine: 2.0 m-kg (14 ft-l b) Spark plug 0.9 m-kg ( 7 ft-lb) Cam cap nut 3.8 m-kg (27 ft-lb) Rod cap (22 ft-lb) 3.0 m-kg Starter clutch bolt 1.7 m-kg (12 ft-l b) Shift cam locating bolt 4.3 m-kg (31 ft-l b) Detent assembly...
  • Page 146 Middle gear case: 375cc(12.7 U.S. f l o z ) Final case: 300cc(10.0 U.S. f l o z ) gear (PAGE 26) Cam Chain Adjustment (XS750-2D) The cam chain tensioner stopper bolt i s the right (inboard) side of the located 1. Adjustor...
  • Page 147 (PAGE 37) Muffler, Footrest, Brake Pedal (XS750- 2D Only) The muffler has been changed from into 2. into 1 to Brake rod 4.
  • Page 148 (special t oo l) t o tighten the clutch nut. NOTE: Bend over locking tab after locknut is (PAGE 73) tightened. Piston and Cylinder (XS750D. XS750- Clutch n u t torque: Position piston rings as shown. 12.0 f t-lb ) m-kg...
  • Page 149 T.D.C. on the power stroke in the left cylinder (No. (PAGE 82) cylinder). 5-2. REAR WHEEL (XS750-2D Only) "T" 4. Align the timing plate tip with the mark on the governor for the l eft cylin- Removal der (No.
  • Page 150 While supporting the brake caliper, pull 5. Raise the seat and unscrew the rear fen- o u t the rear axle. der installation bolts u n til their threaded portion is completely out. Reinsert those bolts as stoppers while holding the rear fender.
  • Page 151 2. Final gear case splines Rear wheel hub splines 3. Check the battery terminals and couplers for looseness. 4. Connect t w o Yamaha pocket testers to 6-2. CHARGING SYSTEM (XS750-2D Only) the regulator coupler as illustrated. Charging Circuit Diagram...
  • Page 152 Checking Silicon Rectifier 1. Check silicon rectifier specified using Yamaha pocket tester. Turn the main switch on. Make sure that V 2 i s than1.8V. less NOTE: Do n ot turn o n lights or signals.
  • Page 153 CAUTION: The silicon rectifier can be damaged if subject to overcharging. Special care should be taken to avoid a short circuit and/or incorrect connection of the posi- tive and negative leads at the battery. Never connect the rectifier directly to the battery to make a continuity check.

This manual is also suitable for:

Xs750dXs750-2d