Today I bought a BR 550 Stihl Backpack blower. I was looking and noticed that BOTH have 64.8 cc engines. They both have the same engine but the 600 produces 3.8 bhp and the 550 produces 3.4.
The 600 also produces 712 cfm vs 550 producing 530.
How does the 600 gain the extra bhp and the CFM?