modder
ArboristSite Operative
Mine is still 44mm top end with the side transfer covers. From what I read, that is the same top end the 2150 started with before it went to the 45mm (52cc) top end. I am sure they just did it to save $ in production costs, just as they later used the same top end for the 2150 and 2152 but in 45mm. They used different pistons in those models though.