ORIGINAL: Ed Cregger N2ECW
Too much prop. Try a 10x6 and see the difference.
Also fatten the mixture up a tad. You're running it way too lean. You don't have to over lean this engine when running a 10x6. I'd like to strangle the person that spread the rumor that these engines run best with an 11x6, or heavier, prop.
Ed Cregger
Next time I'm in the US, I'll pop in for a strangling.
The TT .46 pro runs fine with an APC 11 x 6 (about 11.5 - 12K), an MA 11 x 6 (mid to high 13K), an APC 12.25 x 3.75 (11.5 - 12 K), an APC 11 x 5 and an APC 12 x 4 (both mid to high 13s). The only application you'd run a 10 x 6 or a 9 x 7 on a TT .46 Pro is in a Q500 or similar.
We used to run 10 x 6 props on our baffle piston .40s in the seventies. A modern .46 is in a whole-nother realm, powerwise.