Troy-Bilt 721, 521 manual Models, Ref. No, Part Description

Models 521 & 721

Ref. No.	Part No.	Part Description	Ref. No.	Part No.	Part Description
1.	684-0174	Upper Chute Crank Assemby	31.	710-0451	Carriage Bolt
2.	684-0177	Lower Chute Crank Assembly	32.	710-0642	TT Screw 1/4-20 x 0.75”
3.	684-0178	Bracket Assembly: Mitten Grip	33.	710-0773	TT Screw 3/8-16 x 0.5”
4.	731-04075	Shroud (Model 521)	34.	710-0896	AB Screw 1/4-14 x 0.625”
	731-2569	Shroud (Model 721)	35.	710-1005	B Screw 1/4-14 x 0.5”
5.	710-0895	TT Screw 1/4-15 x 0.75”	36.	711-0848A	Axle Tube
6.	710-1003	B Screw #10-16 x 0.625”	37.	712-0116	Jam Lock Nut
7.	710-1882	Hex Fl. Screw 5/16-18 x 1.5”	38.	712-3010	Hex Nut 5/16-18
8.	710-3083	Hex Bolt 5/16-18 x 1.375”	39.	712-3027	Lock Nut
9.	712-0252	Jam Nut	40.	731-1033	Shave Plate
10.	712-0429	Lock Nut	41.	732-0357A	Extension Spring
11.	712-3010	Hex Nut 5/16-18	42.	736-0108	Flat Washer
12.	714-0104	Cotter Pin	43.	736-0119	Lock Washer
13.	714-0507	Cotter Pin	44.	736-0176	Flat Washer
14.	720-0201A	Knob: Chute Crank	45.	736-0242	Beleville Washer
15.	725-0201	Ignition Key	46.	736-0326	Flat Washer
16.	725-2018	Switch: Electric Start Key	47.	736-0329	Lock Washer
17.	726-0100	Push Cap	48.	741-0475	Plastic Bushing
18.	736-0119	Lock Washer	49.	741-0600	Ball Bearing
19.	736-0185	Flat Washer	50.	746-0910A	Clutch Cable
20.	736-0225	Internal Lock Washer	51.	748-0234	Shoulder Spacer
21.	736-0400	Flat Washer	52.	756-0313	Flat Idler
22.	736-0451	Saddle Washer	53.	784-5174	Bearing Cup
23.	7519636	Mitten Grip Handle	54.	784-5175B	Bracket: Brake Idler
24.	684-0190	Spark Plug Access	55.	784-5176	Belt Cover
25.	749-0711A	Upper Handle: Gull Wing	56.	784-5485	Auger Assembly
26.	749-0796B	Lower Handle	57.	784-5720	Chute Crank Bracket
27.	710-0167	Carriage Screw 1/4-20 x 0.50”	58.	684-0196	Auger Housing Assembly
28.	710-0191	Hex Bolt	59.	734-1797	Wheel Assembly
29.	710-0323	Machine Screw	60.	710-1090	Hex Fl. Screw 5/16-18 x 1.25”

30.710-0352 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-

xxxxis painted powder black, the part number to order would be 700-xxxx-0637.

Powder Black: 0637

MTD Red: 0638

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