Originally Posted by
rc4flying
Just would like to add my 2 cents.
Being you are getting air bubbles in the fuel line; I personally would like to see you change to clear Festo fuel tubing from fuel tank to UAT and onto the fuel pump. As of now, you can't tell if there are any bubbles in the Viton tubing. You need to be able to monitor the full length of the fuel line system to accurately troubleshoot for the area causing the bubbles.
I once had a gas engine fuel system causing air bubbles in the fuel line and the engine to flame out. It turned out to be a bad fuel pickup in the fuel tank causing the bubbles. I would have never suspected that problem without changing to clear line to do the true troubleshooting needed. The pickup was the bubble causing culprit. Changed the pickup, problem solved.
I'm not saying the pickup is your problem, but you need to follow the total length of the fuel line.
I have been flying my Rebel Pro for years now with 6mm Festo line. 6mm Viton inside tank and 8mm overflow line and have never had any flameouts caused by bubbles.
Hey there Joe…How’s things?
I spoke with Joey yesterday and also suggested changing the fuel line from the UAT to the pump to a clear polyurethane 6mm line. He actually has “anti-static” 6mm line and not viton as suggested by contributors. To me, if there was an issue in the pickup inside the tank, would there not be more air in the UAT? Just thinking out loud.
I’m in agreement with Dansy that the issue is between the outlet of the UAT, the inlet of the fuel pump, or the pump itself. Since the 4mm line to the turbine is on the pressure side, if there was a leak, it would spew fuel rather than suck air there. But there is a bubble showing there, so it has to be coming in from the suction side.
I do think, Joey is pretty near to solving the issue he’s experiencing.
Wayne