carb says 21-85 Walbro... Doing a c.i.d. formula of the internet, bore x bore x stroke x .7854 it comes to approx 5.0 cid. Hard to measure real good but I used conservative measurements. Dont have a clue as to brand though. Don't know how to get a muffler for it? Dont know what it is. Approx 40mm across the muffler bolt hole center to center..