ORIGINAL: WCB
Let me run this by you guys and see what you think. My DLE30 V2 runs great at all attitudes, however, when I do a vertical figure 8 and come out on the last part (bottom) of the 8 from being inverted back to level the engine sputters and almost dies every time. It only does it at the exact same spot in that maneuver every time and it does it no matter what the throttle setting is. I put the plane in every extreme positive/ negative G maneuver I know how to do plus inverted flight, outside loops with snaps at the top..you name it and it doesn't miss a lick. I checked the clunk and there are no problems with the tank. The engine is on a CG Sukhoi and it has about 1 gal of gas through it, Xoar 19x8 prop, Pennzoil at 32:1.
I can't figure out why it only does it in that one place in that figure 8 and nowhere else.
Any ideas?
Thanks
Bill
My guess is that there is a change in pressure inside the cowl that is affecting the carb's ambient pressure reference diaphragm, which is located under that little square plate with the hole in it. This can definitely make the engine run as you described.
The solution is to solder a nipple in the plate where the little hole is, and to run a piece of fuel tube back inside the fuse where the air pressure remains constant. I have done this a few times and it has worked every time.
[link=http://www.rcuniverse.com/forum/fb.asp?m=9519870]Here[/link] is what it should look like.