Cranking up a reed valve cox on bladder pressure.

Were certainly not dealing with Combat Specials here. My suggestion about the fuel being thrown into the element was strictly due to how the engine reacted prior to going into the outside loop. You do here the engine go rich which is very typical of an engine mounted on it's side due to the g-forces of the fuel being forced up the bypass. I can't explain as to why the engine won't lean completely. I do feel however that Jim did in fact did leave marginal room on his setting in the event the engine unloaded due to the burbling richness in level flight. The reed could be suspect here and my experience with trying to run a reed on bladder is none. I do know that many times certain engines do go rich in the outside no matter what fuel system your running. As to why his needle is only open a 1/4 turn at this point in unexplainable. I personally would press in a new spraybay and needle as something in there sounds suspect. I for one have discovered 3 types of different threads on these needles. I never found a 128tpi needle that had a black finger knob on them. This doesn't mean they don't exist, just my experience. I've only found the fine threaded needle to only be available on the red production back plate. This would also include the postage stamp as well. Again, I'm basing my findings from my stock of parts over the years and I'm not educated enough in the field of Cox backplates to say what was made and what wasn't. I do know when it comes to discovering one, I screw it into my Kustom Kraftmanship Tee Dee spraybar to insure that indeed I do have the proper thread. I also don't generally have these needles almost closed down as in Jim's situation.

In regards to the Combat Special, this past weekend I was trying to run a few and was faced with nothing but problems. These engines, as violent as they may sound are generally real puppy dogs when it comes to user friendly. Yes, I typically launch so rich that I have to continuously keep pinching the bladder prior to launch as the fuel is just pouring into the case. The higher the nitro the richer the launch that's required. For reasons unknown, I couldn't get my engines to run. Maybe the weather?, maybe the planets weren't aligned. I can just say that regardless of experience and knowledge, were all going to be plagued by the bad engine run day and nothing other than experimentation and patience is going to solve these problems.Ken