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+--- Thread: 820 starter cup (/showthread.php?tid=2091)
RE: 820 starter cup - Brad Rose - 02-26-2018
Are the keys readily available for the stepped cranks at any lawn mower repair or auto parts store?
Brad
RE: 820 starter cup - ted johnson - 02-26-2018
No. 506 American Std, SSS No. 8 is the clutch side key. Some shops have them, or just order some from McMaster Carr and have some spares on hand. Ted
RE: 820 starter cup - Brad Rose - 02-26-2018
Your the man Ted!!
Thanks!
RE: 820 starter cup - ted johnson - 02-26-2018
Thanks, Brad. I'm no Louie F., Dave B. or Steve W., but we always try! Ted
RE: 820 starter cup - doug tenney - 02-27-2018
This has nothing to do with the title of the thread, but... it was a pain figuring this out, so I figured I'd share it.
[Mr. Luciani, if you concur with these numbers, it might be good to put them somewhere... unless you already have.]
On the PTO side, Mc91x cranks use a Woodruff key defined by these numbers: SAE #213, ANSI #403, McMaster-Carr #98481A075. The slot in the crank is nominally 0.336" long.
(Mc92 and Mc93 cranks are 0.100 longer on the PTO side, and have LH threads, like Teddy said. The extra length was added when Space Chain came along. Without this extra length, the chain has to eat its way into the block for clearance.)
Older McCullochs (sorry, I don't know the cut-over) use a larger key on their PTO: SAE #3 = ANSI #404 = McMaster-Carr 98481A090. The slot in the crank is nominally 0.444" long.
WB610/WB820/US820 with the kart-type 5/8" - 9/16" stepped crank use a Woodruff key defined by these numbers: SAE #8 = ANSI #506 = McMaster-Carr 98481A120. Basically, same as Teddy said.
The ANSI 3-digit numbering system, defined in ANSI B17.2:
1st digit = width in 32nd's of an inch. 4/32 = 1/8".
2nd and 3rd digits = dia of the Woodruff key's "circle" in 8ths of inch.