My flying buddy has one, which he just moved into a reworked profile cardinal. Surprised he missed this thread actually.

He won't mind me saying, as he admits himself, that he builds heavy, so his cardinal is in the high 50 ozs (built up take apart fuselage - with sukhoi looks). The XZS pulls it around quite ably on 64 foot lines and he performs a fairly respectable schedule with the combination.

Nice motor, easy starting and loads of power, fairly frugal with the fuel as well, last conversation I had on the subject it was consuming close to 3 oz per flight.

Both of us have been using the plain bearing 40 and 45 (SS4_PL) lately as they use the same crankcase and weigh the same. Again they start easily, provide lots of power and are fairly frugal with fuel. Different crankcase to the XZS though.

The only downside to the XZS I can see is the smaller crankcase, so in the unlikely event that you do need more power you'd have to rebuild the nose to get a larger capacity motor to fit, whereas with the plain bearing 40 you can drop in a 45 if you run into trouble.

What is recommended fuel for 40XZS Pro?  What prop are you running? Did you order direct from Enya web site or KAZ?

I have one on a overwight Nobler and it hauls it around very good. Same fuel and prop as was suggested. I also have a 45 that have not found a home for yet.