I have a regulator but I remembered it's capacity wrong (I remembered it was quite low), but I realized just now it's actually 3 amp capacity. So I could have used that because 3 amp should be plenty. Too late as I ordered a new 5 cell nimh. Oh well. Maybe I'll still get a rx lipo if I really need to lighten it up (I don't have any 2S lipos already as I don't fly anything 2S).
ORIGINAL: nmking09
46AX muffler fits but you'll need to do some cutting. Skip the pitts, if you upgrade, and go with either a Ultrathrust or a Jett muffler. Much more power that way. You'll gain about 2-3K rpm, but pay with your hearing.
I did end up ordering a pitts muffler a couple of days ago. It's a light weight SlimLine Q series.
So the only "light" components on the set-up will be the muffler and the 46AX itself (being the minimum size engine but still pretty powerful for it's size). Everything else (servos, etc) will be on the heavier side. So until I put a stronger 4 stroke on it, it won't be much of a "performer" I guess.