ORIGINAL: mstam1971
ORIGINAL: BOUND_4_HELL
I have attempted to tune the needles on several occasions, but cannot get the burbling out with the 22x8, you can hear it burbling, gurgling and farting in this short clip of my Pitts in knife-edge at a 1/4 to 1/3 throttle with the 22x8 Xoar. Also in the video my exhaust pipe had fallen off the muffler, so it may also have something to do with all the burbling.
The power is great and it has never flamed out, but like you, I think it would be nice to have our cake and eat too.
Doesn't sound good.
What are you running for the ignition? Spark plug? Gap distance?
Do you have a hole in the firewall behind the carb?
Do you run or have you considered running a line from the carb vent into the fuselage?
Prop size shouldn't make any difference.
Thanks for the info, first let me say that on that video the end cap from the muffler may have been blown out, first the exhaust pipe then the end cap. I cant be sure when the end cap blew off, because I did not notice until the end of the next day's flying. The exhaust may be venting to atmosphere, no muffler to speak of. I have now bought a Bison Pitts style muffler, it wont be so loud.
I have an NGK M6 spark plug, gapped at 18 thou.
I have a carb vent into the fuselage tube, but no canister on the end.
My ignition is running at approx 4 volts, one of things I have been meaning to try, is to install a two cell LiPo and a regulator, this would bring my voltage to 5.2. but I do not believe this is my problem it ran good with this same set up. However, one never knows until it’s tried.
I do not have a hole in the firewall and I do not relish the thought of doing so, as the fuselage would end up with fuel spit. The carb is 15/16 away from the firewall; it should be breathing OK, as I get a good static RPM of 7240.
The High Speed needle is set to Max RPM and backed out 100 RPM. The Low needle is set so lean, I need to warm up the engine for about 30 sec, in order to accelerate it without dying. Once warmed up the DL50 has never quit in the air.
One more thing I need to look at is the order of the gaskets on the carb, as I did take it apart to clean the filters etc... after the bad landing and cracking the 23x8 prop. It had a lot of dirt and grass around the carb area. There is a possibility I may have reassembled them wrong.
Unfortunately I did a couple of things including changing props at the same time, so I will need to back track to see which one changed the DL for the worse. It was such a nice week up here that I just wanted to fly. Even as bad as it sounds with very little of the muffler that remained, it's never let me down and can pull that 20 lbs Pitts like there is no tomorrow.
The original muffler is something to be desired, I have gone through two of them..... Hope the Bison last longer.
Geppino