[Joe K]

The crank pulley is "located" to a spot on the crankshaft by a "slot" which matches the single key which holds the crank small timing gear. This slot and key keep the pulley from turning by itself.

If the whole crank pulley including it's sleeve is turning then there is chance that the crank pulley "ratchet nut" (the one which the starter crank ratchets into) may have backed off and the whole crank pulley has moved forward. The slot thusly loses engagement with the key and allows the crank pulley to turn relative to the crank.

The solution (and a check) involves removing the ratchet nut, removing the crank pulley, examining for the key and slot to be sure they are not damaged, and then reassemble keeping the pulley slot aligned to the gear key, and tightening the ratchet nut down.

You will find that the crank pulley sleeve has a short "taper" at its innermost end: this taper is by design and allows one to remove the crank pulley and a way for the sleeve to "re-compress" the rope packing on timing cover and oil pan as you push it back into place.

If you have a one piece crank pulley you will have to pull the radiator to do this. You MAY have to un-do the front motor mount either below the frame, or at the two horns. If you have to do this be sure to loosen the four bolts holding the motor into the rear mounts. Then you can use a board and a jack and lift the front of the engine only to get clearance to remove the crank pulley.

A two piece crank pulley you probably remove the radiator for convenience (and prevent bashing in the fins on the back side) but the two piece pulley/sleeve (two parts) can be removed without elevating the motor.

Hope this helps.

Joe K