ORIGINAL: airraptor
Hey freak I still think you have to much pitch and not enough thrust to pull it in the air. the Four's need the higher pitch because of the lower rpm. I would try an 11.5x7 bolly or an apc 12x7 and cut about 3/16 of the tip.
The nine pitch is to much for the drag of this plane if those props are not enough in the air the increase the dia. by one inch. the extra trhust will help in the corners and then unload more in level to get your top end. have some one with a radar gun to verify speed. This is what I would do and it is your plane, these are just suggestions.
I agree here......
The engine is running well. You may want to prop it to turn a bit lower than 16,000 rpm on the ground. Closer to 15,500 would probably be better. If need be lengthen the pipe 1/4" or so.
Try an 11x7, 11x8, 11x9 ..... get some blade area out there....... that is a draggy airframe. Lots of frontal area. It will probably not be slower, and as noted it will get off the line quicker and corner exit speeds will be better.
Of course, get the carb situation taken care of. If the carb does not seem responsive to needle settings (no needle range), you may have the pipe set a bit too critical (too short). Set it back to the default needle settings (mid and low range)... get the top end set first, then work back on the transition.
Expect it to load up a bit in transition - a short pipe like that will tend to do that as it tries to stage. The high end mixture is set to run when on the pipe, and while in flight. That requires "X" amount of fuel. When on the ground, you open the throttle to full, and the engine takes a bit of time getting up on the pipe and to rpm. It will be rich at that point since its receiving the "flight" fuel while at or below ground peak rpm. Its just the nature of a high timed/higher rpm setup. Also, if the midrange is set lean enough to transition up smoothly, throttling down off of the pipe into midrange can create a very lean condition you cut off the fuel with the throttle, but the pipe/engine remain at rpm for a moment.... this is actaully where most people blow glow plugs.