I am not sure about ys. I have flown nothing but 2 stroke's. I just got my first 4 stroke. A Satio 72. I gotta tell ya. THIS THING ROCKS !!!!!! My 540 went from real good to AWSOME ! It is soooo over powered it's silly. Gotta love it.

Ya it's 4 oz's heaver than the 46, and yes it's $110 more but you know what? I DON'T CARE !!!!!!!!

They say that once you try a 4 stroke you will never go back. I think this is very true. Now i am looking at the little satio 40 for my .25 profile.

If your thinking about trying one don't wait !! Just do it. You will not regret it.