Changing the subject here slightly

The Homelite 25's and 30's were made for several years and there are variations in them

Some early 25's had a Forged crank in them I understand? The new ones have a crank assembled from billet parts?

Also, many cylinders are held on with 10-24 self tapping screws but some 30's had #12 screws which are hard to come by.

The self tapping screws are best thrown away and regular hex socket (Allen) screws put in their place.

The old long shaft engines are 3/8" and the shorts are 5/16"

The newest ones with the Ryobi and Cub Cadet names on them may be metric?