First..........go back to page 25 and read post #616.
With the Dub Jett style muffler, everythings OK, but can't use it due to our clubs' noise restrictions.
Using the supplied EVO NX muffler, I just couldn't get any performance. It's like the supplied muffler is strangling any performance. I could not tune out a leaning condition on any outside maneuver and was constantly popping plugs even with the use of the head shim gasket kit. I saw some fuel foaming at the carb line so I installed a smaller tank completely covered in foam.......same annoying lean-out !
After a lot of frustration, and wasted time, I finally got rid of the EVO NX and installed an O.S. 65AX.
Now I've got a nice dependable quiet engine and plenty of power...........not screaming power......but dependable power !
Only downside is I had to re-butch the cowl for the O.S.[:'(]
Total weight not too bad at 8.5 pounds.
Put a couple of break-in flights on the new engine today. So far so good..........
Bottom line is now I'm a happy camper !
I've also got a Hangar 9 Jackal and will probably use the same powerplant.