Models 521 & 721
15
9
1
6
2
6
17
6
14
24
21
21
23
3
1
8
22
13
10
4
2
20
25
16
7
3
3
11
5
7
3
5
45
48
32
42
12
1
9
47
18
31
4
4
26
58
11
35
41
53
49
60
4
2
36
28
37
52
5
5
33
27
29
59
5
54
50
51
4
9
43
35
56
40
53
38
46
34
55
39
30
2
5
Models 521 & 721
Ref. No.
Part No.
684-0174
Part Description
Ref. No.
Part No.
710-0451
Part Description
Carriage Bolt
1
2
3
4
.
.
.
.
Upper Chute Crank Assemby
Lower Chute Crank Assembly
Bracket Assembly: Mitten Grip
Shroud (Model 521)
Shroud (Model 721)
TT Screw 1/4-15 x 0.75”
B Screw #10-16 x 0.625”
Hex Fl. Screw 5/16-18 x 1.5”
Hex Bolt 5/16-18 x 1.375”
Jam Nut
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
684-0177
684-0178
731-04075
710-0642
710-0773
710-0896
710-1005
711-0848A
712-0116
712-3010
712-3027
731-1033
732-0357A
736-0108
736-0119
736-0176
736-0242
736-0326
736-0329
741-0475
741-0600
746-0910A
748-0234
756-0313
784-5174
784-5175B
784-5176
784-5485
784-5720
684-0196
734-1797
710-1090
TT Screw 1/4-20 x 0.75”
TT Screw 3/8-16 x 0.5”
AB Screw 1/4-14 x 0.625”
B Screw 1/4-14 x 0.5”
Axle Tube
7
31-2569
5
6
7
8
9
.
.
.
.
.
710-0895
710-1003
710-1882
710-3083
712-0252
712-0429
712-3010
714-0104
714-0507
720-0201A
725-0201
725-2018
726-0100
736-0119
736-0185
736-0225
736-0400
736-0451
7519636
684-0190
749-0711A
749-0796B
710-0167
710-0191
710-0323
710-0352
Jam Lock Nut
Hex Nut 5/16-18
Lock Nut
Shave Plate
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
0.
1.
2.
3.
4.
5.
6.
7.
8.
9.
0.
1.
2.
3.
4.
5.
6.
7.
8.
9.
0.
Lock Nut
Extension Spring
Flat Washer
Hex Nut 5/16-18
Cotter Pin
Lock Washer
Cotter Pin
Flat Washer
Knob: Chute Crank
Ignition Key
Beleville Washer
Flat Washer
Switch: Electric Start Key
Push Cap
Lock Washer
Plastic Bushing
Ball Bearing
Lock Washer
Flat Washer
Clutch Cable
Internal Lock Washer
Flat Washer
Shoulder Spacer
Flat Idler
Saddle Washer
Bearing Cup
Mitten Grip Handle
Spark Plug Access
Upper Handle: Gull Wing
Lower Handle
Bracket: Brake Idler
Belt Cover
Auger Assembly
Chute Crank Bracket
Auger Housing Assembly
Wheel Assembly
Hex Fl. Screw 5/16-18 x 1.25”
Carriage Screw 1/4-20 x 0.50”
Hex Bolt
Machine Screw
B Screw1/4-14 x 0.375”
NOTE: For painted parts, please refer to the list of color
codes below. Please add the applicable color code,
wherever needed, to the part number to order
a
replacement part. For instance, if a part numbered 700-
xxxx is painted powder black, the part number to order
would be 700-xxxx-0637.
Powder Black: 0637
MTD Red: 0638
2
6
Models 521 and 721
19
16
24
18
1
15
7
5
11
10
15
8
17
Engine is for reference only
and may not resemble the
engine on your snow thrower.
9
6
13
25
3
21
13
14
23
2
3
4
22
20
Ref. No.
Part No.
629-0071
Description
Ref. No.
14.
Part No.
Description
1
2
3
4
5
6
7
8
9
.
.
.
.
.
.
.
.
.
Extension Cord
736-0242
Beleville Washer
Lock Washer
Plastic Bushing
Fuel Line Hose
Gas Tank
710-0157
710-0409
710-0502A
710-0751
710-1003
710-3013
712-3006
719-0581
726-0205
731-2825
736-0119
Hex Bolt 5/16-24 x 0.75”
Hex Bolt 5/16-24 x 1.75”
TT Sems Screw
15.
736-0329
741-0475
751-0535
751-0540A
751-0603
754-0101A
756-0416B
756-0475
784-0322
784-0323
784-0374
16.
17.
Hex Screw 1/4-20 x 0.620”
B Screw #10-16 x 0.625”
Hex Screw 1/4-20 x 0.50”
Hex Nut 1/4-20
18.
19.
Fuel Cap
20.
V-Belt
21.
V-Pulley Half
Pulley
Spacer
22.
1
1
1
0.
1.
3.
Hose Clamp
23.
Engine Mount
Support Bracket
Choke Knob
24.
Lock Washer
25.
Support Plate: Engine Mount
2
7
Models 521 and 721
Ref. No.
Part No.
710-0487
Description
Carriage Screw 5/16-18 x 2.0”
Machine Screw
5
1
2
3
4
5
6
7
8
9
.
.
.
.
.
.
.
.
.
9
710-1270
712-0324
720-0284
720-0295
725-0157
736-0451
746-0883
747-0956
Hex Lock Nut 1/4-20
Hand Knob w/ Wing Nut
Foam Grip
Cable Tie
Saddle Washer
8
10
Control Housing
3
Auger Bail
1
0. 749-0711A
Upper Handle: Gull Wing
2
4
7
NOTE: For painted parts, please refer to the list of
color codes below. Please add the applicable color
code, wherever needed, to the part number to order a
replacement part. For instance, if a part numbered
700-xxxx is painted powder black, the part number to
order would be 700-xxxx-0637.
1
6
7
Powder Black: 0637
MTD Red: 0638
4
5
Ref. No.
Part No.
710-04071
710-0451
710-3015
712-3027
712-3068
720-0284
731-0851A
731-0915C
731-0921
736-0159
Description
Carriage Bolt 5/16-18 x 1.0”
Carriage Bolt 5/16-18 x 0.750”
Hex Screw 1/4-20 x 0.75”
Lock Nut
9
1
2
.
.
10
10
6
3.
4
5
6
7
8
.
.
.
.
.
Hex Lock Nut
8
4
Hand Knob
Flange Keeper: Chute
Lower Chute
1
2
9.
0.
Upper Chute
1
Washer
4
7
3
2
8
