750 SF2 crankshaft sprocket lock washer

[murphus]

Can someone educate me as to how the lock washer for the crankshaft sprocket nut is supposed to, well, be locked? Whoever was in the primary last time left the crankshaft nut literally hand tight, with the lock washer hammered up on one flat. There was a vestigial tab on the washer, bent to a right angle from the face of the washer. The lock washer reminds me of what's used under the adjusting nut on an automotive hub with tapered bearings, e.g., the tab locates in a recess on the axle so it won't spin. But of course there's no recess in the crank end. What am I not understanding?

 

[Tippie]

On all the cranks I have done, the tab washer can wriggle into position into a spline outside the sprockets. That it was loose doesn't mean that it was assembled to run just hand tight, they can work loose unless there is extreme torque on that "Jesus" nut. The washer won't stop this working loose if there is insufficient torque on the nut, but will prevent it falling off out to the cover. There is usually very little to bend over on those washers, Phil Todd's washers had more.

 

[sfcpiet]

Bend the tab to a right angle and slip it on, the tab will engage with a spline of the sprocket.

piet

 

[Paul Marx]

Your description of how to mount the washer Murphus is exactly right.

Then apply massive torque to the nut with some Loctite.

Paul

 

[murphus]

OK, so no real mystery. Thanks all, much appreciated.