Stihl 021 clutch drum sprocket

[Keithandstef]

Hello all. Working on an old Stihl 021 and I couldn’t see the numbers on the bar so I purchased a Stihl 3005 000 4713, 16” 0.325 0.63 bar which does fit my saw as best I can tell. Purchased an Oregon 22LPX062 chain which fits the bar just fine. Problem is the chain doesn’t fit my drum sprocket which is a Pico 1123/05 Z6. I’d rather not replace the bar and chain. What drum sprocket do I need, and I guess also, is this set up going to be OK for a 021? I’m not sure why the bar and chain don’t fit since I looked up that they are compatible with this model. Maybe the previous owner switched the drum sprocket? Thanks as always

 

[Keithandstef]

Looks like that socket is a 3/8. And that’s stock for an 021. Seems like a .325 would be better suited for this saw. Guess I’ll grab a .325 sprocket

 

[stihltech]

021 came with picco 3/8. Can you put .325 on it? Sure. Same as 023, 025, MS230, MS250. The sprocket must match the bar and chain.
A word of caution- DO NOT run a larger chain dull on the unit!. You will be making more repairs.