218494 McCulloch Replaceable Sprocket Tip 16" Bar .325 pitch .050 ga 68 Drive Links Vintage NOS.  May be Black or Gray.  Use Rotary chain 7324068.

Also McCulloch 223195 / 218923 / 223195

Numbers on bar are 218494 1650 5630 EL 

SR-Back W7 & W8 & W9

*Make sure your spur or rim sprocket match the pitch of your bar sprocket tip.  Both must be .325" pitch*

If you need to change your sprocket to a .325" pitch you can purchase Rotary 14986 sprocket and purchase the Oregon rim 13624.  The Rotary 14986 sprocket comes with a 3/8" 7-tooth rim, so you have to change the rim out with the Oregon 13624 rim that is .325" pitch 9-tooth and fits the 7-spline sprocket.

The D176 mount fits the following:

• Echo:  CS-60, CS-60S, CS-451, CS-452, CS-500, CS-501EVL, CS-510EVL, CS-550, CS-590, CS-600P, CS-601, CS-602, CST-610, CS-610T, CS-650, CS-660, CS-670, CS-680, CS-701, CS-702, CS-706, CS-750, CS-6700, CS-8000
• Fairmount Hydraulic:  H6200B
• JOHN DEERE:  50AV, 50V, 51SV, 55EV, 55V, 55SV, 60V, 65, 65EV, 65SV, 66SV, 70V, 80EV, 800V
• McCulloch:  1-10, 2-10, 3-10, 4-10, 5-10, 6-10, 7-10, 10-10, 10-10A, 55
• McCulloch:  PRO MAC 55, 60, 555, 560, 570, 605, 610, 620, 650, 655, 700, 800, 850, 1000
• McCulloch:  CP55, CP70, CP70L
• McCulloch:  DOUBLE EAGLE 50, 80
• McCulloch:  EAGER BEAVER 3.7
• McCulloch:  PM 605
• McCulloch:  PROMAC 5700, 8200
• McCulloch:  SILVER EAGLE 3420, 3720
• McCulloch:  SP60, SP70, SP80, SP81
• McCulloch:  TIMBER BEAR (earlier models)
• McCulloch:  TITAN 50, 57, 70
• POULAN / POULAN PRO:  203, 245, 306, 306A, 360, 361, 375, 385, 395, 400, 446, 450, 3400, 3700, 3800, 3900, 4000, 4200, 4400, 4900, 5200, 5400, 5500, 6700
• RED MAX:  G621AVS
• SEARS / CRAFTSMAN:  35212, 35483, 35487, 35608, 35609, 35690, 35721, 35727, 35728, 35826, 35829, 35851, 35881, 35885 ELECTRICS (1983 MODELS AND FORWARD), 35887, 35889
• SKIL:  1641
• TANAKA:  ECS-505, ECS-506, ECS-650, ECS-655