As per Stihl (poster of 051); The 050AV launched onto the market in 1968. Consistently upgraded. The increase in power combined with the installation of an electronic ignition system made it necessary to enlarge the air filter housing thus distinctively changing the machine's shape so that it was finally renamed in Stihl 051AV in 1972.
I believe the 050AV always had the ball bearing at the ignition side and the cylindrical roller bearing at the sprocket side.
So here is our first contradiction. The service manual says; "051 and 075 crankcases are identical (I assume they are not inluding the diameter of the cylinder mounting holes) on machine numbers 9280310 up to 9281309 and from machine number 9422350 onward. On earlier versions of the 051 the crankshaft is supported in a ball bearing at the ignition side and a cylindrical roller bearing at the sprocket side"
Also;
"Early 051 machines had a breaker controlled magneto ignition. As from machine No. 3001400 exclusive use is made of the breakerless (transistor) magneto ignition system."
The poster implied the electronic ignition went on the 050 BEFORE it was renamed????
Here is a picture of a crankcase with the roller bearing, note the two mounts in vertical alignment behind the flywheel to mount the breaker system.
Another;
A later version (breakerless), note the two mounts for the trigger plate, one has a protrusion.
The 075 never had points and AFAIK shared the same ignition as the 051 (without points).
:msp_w00t:
