ErrolC
ArboristSite Operative
Hi guys...can anyone advise crankshaft compatibility of the 660 for a 640...I have a low hrs near mint 640 (not 064) which has run its small end on the conrod...its clearly run through what little case hardening there was (Stihl nz don't want to know about it)...I've been told there are several changes through the years between the 064, 066, 640/660. It's been said to me the flywheel taper/thread size is different as may be the oil pump drive.
