I guees I need to change my name.
IMO sell the stock engine before you even start it and get the Pico .26.The 21bb is a nice reliable engine but it doesn't make good power.I've seen them sell on ebay for as much as 100$ so if you get lucky you can do that and get the Pico for dirt cheap.Make sure and get a set of HD dogbones if you swap engines too.I broke mine with 8port and the Pico makes even more power.