When the engine was on the Pulse, I wanted speed, so I had a 11x6 APC. Turned about 12,300 on the ground, and ran perfect. Tried the same set up on the Venus, and the plane was a little bit too fast for me at full throttle, and took forever too slow down enough to land. I tried a 12 x 7 APC and a 12 x 7 wooden Zinger to see if I could get it to slow down a little. Also bought a 13" prop, but didn't try it. With the 12" prop, the engine was real picky on transition to full throttle. Sometimes it would just die, and other times it would hesitate, gurgle, and keep going. Tried adjusting low end needle and I could get it to run just OK. But, when it was in the air, the mid range was pretty crappy. It would spit and sputter, but keep running. I tried to fine tune it (I will admit that I am no expert, but I understand how it works), but I couldn't get it to run any better. Switched back to an 11 x 7 and an 11 x 6 and it runs perfect. I have read a few other guys have had the same problem. It might just be my tuning abilities are lacking, so for now, I will just fly it at 2/3 throttle for awhile. If you guys can help, I'm open to suggestions. The engine has about 20-25 tanks of gas through it, running PowerMaster 15% nitro, 18% oil. Maybe it's just not broken in all the way?

gaRCfield,
Sorry to jump on your thread. Hopefully you won't have any problems.