Stihl MS251 Specs
Displacement: 2.78 cu. in. (45.6 cm 3 )
Cylinder bore: 1.73 in. (44 mm)
Piston stroke: 1.18 in. (30 mm)
Engine power: 3.0 hp (2.2 kW) at 10,000 rpm
Idling speed: 2,800 rpm
Maximum permissible speed with bar and chain: 13,000 rpm
Weight: 1.0 lbs. (4.9 kg)
Fuel tank capacity: 13.2 fl.oz (0.39 l)
Oil tank capacity: 6.7 fl.oz (0.2 l)
Spark plug gap: 0.02 in. (0.5 mm)
Stihl MS251 part numbers lookup
1141 120 1600 Air filter
1143 080 1601 Air filter cover
1143 790 8301 AV spring
1143 790 8302 AV spring
16" Bar
18" Bar
0000 955 0801 Bar nut
1143 664 0500 Bucking spike
1143 120 0601 WTF-2A Carburetor
16" Chain
18" Chain
1143 160 5401 Chain brake band
1143 021 1101 Chain brake cover
1143 792 9103 Chain brake guard
0000 656 7700 Chain catcher
1123 160 2050 Clutch
1143 648 0401 Clutch cover
1143-030-0401 Crankshaft
9638 003 1581 / 9639 951 1584 Crankshaft oil seals
9503 003 0340 Crankshaft bearing
1143 020 1207 Cylinder and piston kit
1143 080 1601 Cylinder top cover
1143 400 1201 Flywheel
0000 350 0533 Fuel cap
4224 122 3900 Fuel elbow connector
0000 350 3518 Fuel filter
1143 358 7700 Fuel line
1143 350 0807 Fuel tank housing and rear handle
1143 400 1307 Ignition coil
1143 791 0600 Handle trigger cover
1143 791 1706 Handlebar
1143 140 0651 Muffler
9512 003 2331 Needle cage bearing 10x14x12.5
9512 933 2260 Needle cage bearing 10x13x10
0000 350 0533 Oil cap
1143 647 9401 Oil hose
1143 647 9403 Oil line
1143 640 3201 Oil pump
1143 030 2007 Piston 44mm
1143 034 3007 Piston rings
1143 007 1003 Rim sprocket kit .325" 7T
0000 642 1234 Rim sprocket .325" 8T
0000 642 1240 Rim sprocket 3/8" Picco 7T
Champion RZ7C Spark plug
NGK CMR6H Spark plug
1141 791 3102 Spring
1123 007 1004 Spur gear chain adjusting screw kit
1143 080 2107 Starter assembly
1121 195 3400 Starter handle
1143 182 0900 Switch shaft
1143 182 1500 Throttle rod
1143 182 1000 Trigger
Stihl MS251 Chain Size
.325"
Low kickback STIHL saw chain (with green label)
Rapid Micro 3 (26 RM3) Type 3634
Rapid Duro 3 (26 RD3) Type 3667
Pitch: .325" (8.25 mm)
Drive link gauge: 0.063 in. (1.6 mm)
3/8"
Low kickback STIHL saw chain (with green label)
Picco Micro 3 (63 PM3) Type 3636
Picco Super 3 (63 PS3) Type 3616
Picco Duro (63 PD3) Type 3612
Pitch: 3/8" P(9.32 mm)
Drive link gauge: 1.3 mm (0.050 in)
Stihl MS251 Part Number Lookup List
Motor housing:
# 1143 020 3023 Engine housing
2 1143 020 3025 Engine housing (MS251C-BE, MS251C-BEZ)
3 1143 020 3027 Engine housing (MS251C-BEQ, MS251C-BEQ Z)
4 1128 640 9100 Valve
5 1123 664 2400 Collar screw
6 1143 664 2401 Collar screw
7 1123 664 2405 Collar screw D9/M8 (B) 29.2011
8 1123 640 3800 Pickup body
9 1143 647 9401 Hose
11 1143 791 5900 Stop buffer
12 0000 350 0537 Filler cap 13 8.2012
13 9645 948 2470 O-ring 23x3 8.2012
14 1143 140 7800 Pre-separator
15 9074 477 2995 Pan head self-tapping screw IS-P4x12
16 0000 656 7700 Chain catcher (B)
17 9074 477 4438 Pan head self-tapping screw IS-P6x30 (B)
Cylinder:
2 1143 020 1207 Cylinder with piston Ø 44 mm
4 1143 030 2007 Piston Ø 44 mm
6 1143 034 3007 Piston ring Ø 44x1.2 mm
7 1143 034 1500 Piston pin 10x8x27.88
8 9463 650 1000 Snap ring 10
9 1143 030 0401 Crankshaft
11 1143 020 1211 Cylinder with piston Ø 44 mm PRC
13 1143 030 2029 Piston Ø 44 mm PRC
15 1143 034 3011 Piston ring Ø 44x1,2 mm PRC
16 1143 030 0409 Crankshaft PRC
17 1143 140 2501 Manifold
18 9075 478 3012 Pan head self-tapping screw IS-D4x12
20 * 1143 020 1203 Cylinder with piston Ø 44 mm
23 * 1143 140 2500 Manifold 54.2013
24 * 9075 478 3012 Pan head self-tapping screw IS-D4x12
25 9512 003 2331 Needle cage 10x14x12.5
26 9503 003 0340 Grooved ball bearing 6202
27 9639 951 1584 Oil seal 15x25x5
28 9638 003 1581 Oil seal 15x25x5
29 9468 621 1520 Circlip 15x1
30 1143 021 2502 Engine pan
31 9075 478 4197 Pan head self-tapping screw IS-D5.3x43
32 0783 830 2000 Tube of sealant HT red (B)
Muffler:
2 1143 140 0667 Muffler
4 1143 140 0671 Muffler USA, CDN, AUS, NZ (MS251C-BEZ, MS251C-BEQZ, MS251-Z, MS251-Z WoodBoss)
5 1143 149 0603 Muffler gasket
6 1135 145 9002 Plug
7 1143 140 8103 Spark arresting screen USA, CDN, AUS, NZ
9 1143 140 0401 Cooling plate
10 9022 341 0983 Spline screw IS-M5x16
11 * 1143 140 0651 Muffler
13 * 1143 149 0601 Muffler gasket 54.2
Oil pump, Clutch:
1 1143 640 3201 Oil pump
2 1143 647 9403 Hose
3 9075 478 3016 Pan head self-tapping screw IS-D4x16
4 1123 640 7102 Worm gear 5
5 1123 647 2400 Spring
1123 160 2050 Clutch
6 1121 162 3201 Carrier
7 1129 162 0800 Clutch shoe
8 1127 162 3000 Retainer
9 0000 997 5515 Tension spring
10 1121 162 1001 Cover washer
11 9512 933 2260 Needle cage 10x13x10
12 1143 640 2000 Chain sprocket 3/8" Picco 6T
13 1143 640 2002 Chain sprocket 0.325" 7T
1123 640 2007 Chain sprocket 1/4" 8T (A,B)
1143 007 1002 Rim sprocket kit 3/8" Picco 7T (B)
14 Clutch drum (B,D)
15 0000 642 1240 Rim sprocket 3/8" Picco 7T (B)
1143 007 1003 Rim sprocket kit 0.325" 7T (B)
16 0000 642 1236 Rim sprocket 0.325" 7T (B)
1143 007 1004 Rim sprocket kit 0.325" 8T (B)
17 0000 642 1234 Rim sprocket 0.325" 8T (B)
18 0000 958 1022 Washer Ø 27 mm
19 9460 624 0801 E-clip 8x1.3
Chain brake:
1 1138 160 5000 Lever
2 1123 162 7800 Flat spring
3 1143 162 5802 Strap
4 1141 162 9401 Spacer
5 9460 624 0400 E-clip 4
6 1143 160 5401 Brake band
7 9074 477 2995 Pan head self-tapping screw IS-P4x12
8 1143 162 7901 Tension spring
16 1143 021 1101 Cover
17 9074 477 4132 Pan head self-tapping screw IS-P5x18
For MS251C-BEQ, MS251C-BEQZ:
9 1138 160 5001 Lever
10 1143 162 7914 Tension spring
11 1143 160 5405 Brake band 3/8" Picco 6T
12 1143 160 5403 Brake band 0.325" 7T
13 0000 958 1022 Washer Ø 27 mm
14 9460 624 0801 E-clip 8x1.3
Chain tensioner, Chain sprocket cover:
# 1123 007 1004 Spur gear / chain adjusting screw kit
1 Spur gear (D)
2 Adjusting screw (D)
3 1123 640 1900 Tensioner slide
4 1123 664 1400 Thrust pad
5 1123 664 2200 Cover
6 9074 477 2995 Pan head self-tapping screw IS-P4x12
7 1143 640 1701 Chain sprocket cover
8 0000 955 0801 Hexagon nut M8
9 1143 664 0500 Bumper spike
10 9074 477 4130 Pan head self-tapping screw IS-P5x16
1143 007 1005 Quick tensioner parts (B)
11 1123 021 2800 Insert (B)
Ignition system, Wiring harness:
1 1143 400 1203 Flywheel
2 1143 400 1235 Flywheel (MS251C-BEQZ, MS251C-E)
6 0000 955 0802 Collar nut M8x1
7 1143 400 1315 Ignition module
8 1143 400 1317 Ignition module PRC
9 0000 998 0604 Torsion spring
10 0000 405 1007 Spark plug boot
11 1143 440 3503 Lead retainer
12 9075 478 3022 Pan head self-tapping screw IS-D4x20
13 9291 021 0100 Washer 4.3
14 1143 440 3013 Wiring harness
15 0000 400 7011 Spark plug NGK CMR6H
16 * 1143 400 1201 Flywheel 54.2013 25.2005
18 * 0000 998 1100 Torsion spring 54.2013
21 * 1143 400 1307 Ignition module 54.2013 32.2012
22 * 1143 440 3501 Lead retainer 32.2012
23 * 1143 440 3001 Wiring harness 32.2012
Rewind starter, Hand guard:
# 1143 080 2103 Fan housing with rewind starter
# 1143 080 2107 Fan housing with rewind starter S
1 1143 080 1803 Fan housing 2 8.2012
2 1110 084 9102 Bushing
3 1143 084 7801 Segment
4 1143 190 0600 Rewind spring
5 1143 195 0400 Rope rotor
6 1125 195 7200 Pawl
7 0000 958 0923 Washer
8 1118 195 3500 Spring
9 1121 195 3400 Starter grip
10 0000 195 8200 Starter rope Ø 3x800 mm
0000 930 2208 Starter rope Ø 3 mm x 30.5 m (A,B)
11 0000 190 3409 Starter grip ElastoStart Ø 3 mm S (5)
12 0000 195 8205 Starter rope Ø 3x750 mm S
0000 930 2208 Starter rope Ø 3 mm x 30.5 m (A,B) S
13 0000 195 7001 Cap S (5)
14 9074 477 4132 Pan head self-tapping screw IS-P5x18
Fuel tank housing:
1 1143 350 0807 Tank housing
2 1143 350 0825 Tank housing USA (MS251-Z, MS251-Z WoodBoss)
3 1143 350 0829 Tank housing (MS251C-BEQ, MS251C-BEQZ)
4 1143 350 0833 Tank housing (MS251C-BE, MS251C-BE Z)
5 1143 350 0833 Tank housing S
7 1143 350 0847 Tank housing PRC
8 0000 350 5800 Tank vent
9 1143 358 7700 Hose
10 0000 350 3504 Pickup body
13 4242 353 2600 Elbow connector
14 1143 937 5000 Hose 154 mm
15 1143 353 7000 Cover
16 9074 477 4148 Pan head self-tapping screw IS-P5x34
18 1141 989 0600 Grommet S
20 4242 353 2600 Elbow connector S
22 0000 937 5006 Hose 2.2x5.4 mm x 1 m, R5 (A,B) S
24 1143 353 2601 Elbow connector S
26 9074 478 2970 Pan head self-tapping screw IS-P4x10 S
28 0000 930 2802 Hose 2.2x5.4 mm x 1 m, R1 (A,B) S
30 0000 989 0816 Grommet S
31 0000 350 0533 Filler cap 32 8.2012
32 9645 948 7734 O-ring 25x3.5 8.2012
33 0000 967 7247 Warning pictogram MS
AV system, Handlebar:
1 1143 790 8302 AV-Spring
2 0000 656 7700 Chain catcher (B)
3 9074 477 4438 Pan head self-tapping screw IS-P6x30
4 1141 791 3102 Spring
5 1141 792 2910 AV mount
6 * 1143 792 2902 AV mount 54.2013
7 1143 790 8104 Retainer (B)
8 9075 478 4085 Pan head self-tapping screw IS-D5x18
9 1143 790 8301 AV-Spring
10 9074 477 4148 Pan head self-tapping screw IS-P5x34
11 1143 791 3103 Spring PRC
12 1143 790 8102 Retainer PRC
13 1143 792 2907 AV mount PRC
14 9074 477 4132 Pan head self-tapping screw IS-P5x18
15 1143 791 5900 Stop buffer
16 1141 122 9902 Buffer
17 1143 791 1706 Handlebar
19 9074 478 4545 Pan head self-tapping screw IS-P6x26.5
20 9022 341 0983 Spline screw IS-M5x16
Shroud, Air baffle:
1 1143 080 1601 Shroud
2 1143 080 1607 Shroud USA (MS251-Z, MS251-Z WoodBoss)
3 1143 080 1631 Shroud (MS251C-BE, MS251C-BEZ, MS251C-BEQ, MS251C-BEQZ)
4 1143 080 1631 Shroud S
6 9022 319 1028 Screw IS-M5x14
10 1143 087 3003 Air guide shroud
11 1143 087 3008 Air guide shroud PRC
12 * 1143 087 3004 Air guide shroud 54.2013
13 1143 084 4100 Shutter
15 1143 350 6200 Fuel pump S
17 2 Hose 2.2x5.4x54 mm, R5 (D) S
0000 937 5006 Hose 2.2x5.4 mm x 1 m, R5 (A,B) S
19 1143 353 2601 Elbow connector S
21 9074 478 2970 Pan head self-tapping screw IS-P4x10 S
23 Hose 2.2x5.4x196 mm, R1 (D) S
0000 930 2802 Hose 2.2x5.4 mm x 1 m, R1 (A,B) S
25 0000 989 0816 Grommet S
27 4242 353 2600 Elbow connector S
29 9074 477 2995 Pan head self-tapping screw IS-P4x12
Carburetor bracket, Air filter:
1 1143 120 0901 Carburetor bracket
2 1141 121 8600 Washer
3 1143 120 0611 Carburetor C1Q-S295
4 1143 120 0641 Carburetor C1Q-S296 (MS251C-BE, MS251C-BEZ, MS251C-BEQ, MS251C-BEQZ)
6 1143 120 0617 Carburetor PRC
8 * 1143 120 0601 Carburetor WTF-2A 54.2013
10 * 1143 120 0631 Carburetor WTF-4A (MS251C-BE, MS251C-BEZ, MS251C-BEQ, MS251C-BEQZ) 54.2013
11 * 1143 120 0631 Carburetor WTF-4A S (5) 54.2013
13 9646 945 0490 O-ring 7x1.5
14 1143 141 0903 Filter base
15 1143 141 0905 Air filter base PRC
16 1143 140 4401 Air filter (B) PRC
17 1143 140 4403 Air filter PRC
18 * 1143 141 0901 Filter base 54.2013
19 1141 122 9902 Buffer
20 1143 121 6900 Baffle
21 9216 261 0700 Hexagon nut M5
22 1141 120 1600 Air filter, fleece
Carburetor:
1 1143 120 0611 Carburetor C1Q-S295
2 1143 120 0641 Carburetor C1Q-S296 (MS251C-BE, MS251C-BEZ, MS251C-BEQ, MS251C-BEQZ)
3 1143 120 0617 Carburetor PRC
5 4116 121 5100 Inlet needle
6 1125 121 5000 Inlet control lever
7 1129 122 3001 Spring
8 1120 121 9200 Spindle
9 0000 122 7101 Screw
11 1143 129 0901 Gasket PRC
13 1140 121 4701 Metering diaphragm PRC
14 1143 126 0703 Metering cover
15 1143 126 0704 Metering cover PRC
17 4132 122 6600 Collar screw PRC
18 1129 121 4800 Pump diaphragm
19 1123 129 0905 Gasket
20 1139 121 0800 End cover
21 1120 122 7800 Oval head screw
23 1143 120 6803 Low speed screw PRC
24 * 1143 120 6801 Low speed screw PRC
25 0000 121 2704 Cap
26 0000 121 2703 Cap PRC
28 1143 120 6701 High speed screw PRC
29 * 1143 122 6705 High speed screw PRC
30 1141 121 2704 Cap
31 4229 121 2701 Cap PRC
32 1143 122 6203 Idle speed screw
33 1143 121 2707 Cap
34 1143 121 3503 Throttle lever
36 1125 122 9001 E-clip
37 1123 121 7800 Strainer
38 1143 121 9405 Ring
42 1143 185 1903 Choke rod
44 1143 007 1702 Set of carburetor parts PRC
1143 120 0601 Carburetor WTF-2A
Throttle control:
1 1143 182 1000 Throttle trigger
2 1143 182 4500 Torsion spring
3 1143 182 0800 Lockout lever
4 1143 791 0600 Handle molding
5 9371 470 2680 Cylindrical pin 5x28
6 1143 182 1500 Throttle rod
7 1143 182 0900 Switch shaft
8 1143 442 1600 Contact spring
9 1143 185 1903 Choke rod
10 * 1143 185 1905 Choke rod 41.2014
Tools, Extras:
1 0000 890 3400 Combination wrench
2 0000 890 2300 Screwdriver
3 0812 370 1000 Screwdriver T27x120x70 (B)
4 0000 891 0810 Tool roll (B)
5 1110 893 4000 Filing gauge (B)
Stihl Parts | Stihl Parts Lookup