MIKUNI hsr48x viewdata MIKUNI hsr48x viewdata

HSR48 Data Sheet

This is a temporary data sheet containing important information about the

new Mikuni HSR48mm carburetor.

NOTE: The HSR48 is meant for racing only and may not t onto stock motorcycles

without signicant modication of that motorcycle. Treat it as a true racing part, one
that is meant for custom installations and not as a simple replacement part.

Engines producing more than 120 horsepower should supply fuel from an electric
fuel pump to the HSR48. Do not exceed 4 psi and use the smaller Mikuni Needle
Valve Assembly (p/n: 786-27001-2.3).

Installation:

The HSR48 can mounted to an S&S “G” manifold using a Mikuni rubber ange,
(p/n: HS42/062-48). The rubber ange ts the “G” manifold without modication.

The “G” manifold plus the Mikuni rubber ange does result in the HSR48 protruding
further than the stock Harley carburetor and may touch the gas tank.

Standard Jetting Specications:

Description Size Part Number

Main jet 190 N100.604-190
Pilot jet 25 VM28/486-25
Jet Needle -97 J8-8CFY02-97 (E-clip in 3rd groove)
Needle Jet Y-6 784-430000-Y-6
Pump Nozzle 70 TM42/11-70
Needle Valve: 4.5 786-27002-1A

Additional Tuning Components:

Main Jets: 180 through 240
Pilot Jets: 20 through 35 in 2.5 increments
Jet Needle: -95, -96 (both richer) and –98 (leaner)
Pump Nozzle: -50, -60 (both leaner than std. -70)
Needle Valve: 786-27001-2.3 (smaller - for pressurized fuel feed)

1. C5=0414-B Screw, Top Cover

2. CW2=0416-B Screw, Top Cover (2)

3. 111-776-001 Top Cover

4. TM42/04 Gasket, Top Cover

5. BS32/126 E-Ring, Jet Needle

6. 826-03002 Washer, Needle Clip

7. J8-8CFY02- Jet Needle (HSR45/48)

8. TM42/03 Lever, T.V.

9. B40I/56 E-Ring

10. B40I/10 Packing, Link Lever

11. 834-23041 Pin, Link Lever

12. TM42/08-1A Throttle Valve

13. 739-13002 Screw, Needle Retainer

14. TM42/16 Clip, Needle Retainer

15. TM48/04 Sealing Ring, T.V.

16. TM42/10 Seal, Throttle Valve

17. 925-98006 Pulley, Cable Bracket

18. 53974 E-Ring, Cable Bracket

19. TM42/51 Bracket Assy., Cable

20. B3=0520-B Bolt

21. VM28/204 Spacer

22. TM42/38 Plate, Lock Tab

23. C2=0514-B Screw

24. 640-12001 Guide Holder (Starter)

25. VM14/241 Spring, Starter Plunger

26. N189.192 Starter Plunger

27. TM48/02 Body Assy., Bearing & Spigot (N/A)

28. 616-94029 Seal, Spigot Body

29. 925-19011 Ring (Steel)

30. TM42/43 Lever

31. N138.019 Pin, Throttle Lever

32. TM42/48 Lever, Throttle

33. M12F/46-BB Spring, Accel. Pump

34. MC-0316-B Screw, Accel. Adjust

35. TM42/47 Spring, Accel. Pump

36. TM48SS1/01-0 Mixing Body Ass'y (N/A)

37. B36/95 Packing, Shaft (Plastic)

38. TM42/36 Adjusting Screw, A/P

39. B30/205 O-Ring, A/P Screw

40. TM42/89 Bolt

41. BN38/43 Pin, A/P Lever

42. TM42/46 Lever, Return Spring

43. N140.409 Screw, Throttle Stop

44. N3=04 Nut, Throttle Stop

45. TM42/19 Spring, Throttle Return

46. 700-15012-1A Shaft, Throttle

47. TM42/15 Plate, Fuel Joint Retainer

48. C2=0410-B Screw, Fuel Joint Retainer

49. 604-26014 Screw, Pilot Air Adjusting

50. N133.206 Spring, Pilot Air Screw

51. VM12/205 Washer, Pilot Air Screw

52. N133.037 O-Ring, Pilot Air Screw

53. TM40/27 Fuel Joint

54. KV/10 O-ring, Fuel Joint (2)

55. B30/398 Packing, Idle Adjuster

56. VM22/138 Washer, Idle Adjuster (steel)

57. 730-09018 Spring, Idle Adjuster

58. 925-15001 Ring, Idle Adjuster (Brass)

59. TM42/32 Idle Adjuster Ass'y (Long)

59a. 990-605-065 Idle Adjuster Screw (Short)

60. BS30/97-00 Air Jet (Blank)

61. 784-430000-Y-6 Needle Jet (723 Series)

62. TM42/11- Nozzle, Accelerator Pump

63. N124.063 O-Ring, A/P Nozzle

64. VM28/486-25 Pilot Jet

65. TM42/12-1A Extender, Main Jet

66. N100.604- Main Jet

67. 616-33003 O-Ring, N.V.

68. VM13/216 Screw w/Washer, N.V. Retainer

69. 786-27002-1A Needle Valve Assy. with O-ring (size: 4.5)

70. 859-32027 Float Ass'y

71. BV26/22 Pin, Float

72. C2=0410 Screw, Float Pin

73. 616-94028 Packing, Float Bowl

74. TM42/05 Float Chamber Body

75. N122.028 Hose, Overflow

76. VM28/254 O-Ring, Drain Plug

77. TM32/41-1D Drain Plug

78. C2=0412-B Screw, Float Bowl (4)

79. TM36/44-1B Rod, A/P

80. TM36/64 Boot, A/P Rod

81. TM36/60 Plunger, A/P

82. VM14SC13/89 Spring, A/P

21

45

42

43

44

46

53

54

55

56

57

58

59

4

5

6

7

8

9

10

1

2

3

60

61

62

63

64

65

66

59a

67

69

70

71

72

73

68

82

81

80

79

36

35

52

51

50

49

47

48

40

39

38

41

12

37

11

29

30

13

14

15

16

17

18

19

20

22

23

24

25

26

27

28

31

32

33

34

74

75

76

77

78

40a

HSR48 Carburetor

No. PAR T N o. DESCRI PTION

-50 lean

-60

-70 (std for HSR42/45/48)

-75 rich

-98 lean

-97 (std for HSR48)

-96

-95 rich

83

40a. TM42/17 Lock Tab, Shaft

83. N198.063 Cap, Purge Port

Not legal for sale or
use in California on
pollution controlled
motor vehicles, or
in other states
where similar laws
may apply.

Part Number (000 000) = no available stock

ver: 083101

-190 (std for HSR48)