H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.
Dave C wrote:The T marked number 9, the one on the left side of the diagram, is under suction at all times when the engine or electric fuel pump is running. If it leaked it could suck air.
My 5 year rubber kit, that I got a few months ago from Evektor, has replacement Ts that are now brass instead of aluminum and look more robust.
That is probably what it was then. I don't know a lot about it and all my information came from my instructor showing me a little aluminum T connector and saying it was the culprit because it was causing air to get pumped in and starving the engine when it was at high load, then he tossed it in the trash and we haven't had any problems since. I spent an hour trying to look through Rotax parts to find out what it was before I realized that it was an Evektor specific part and found it by looks in the parts catalogue.
3Dreaming wrote:Did you lose fuel pressure when this was happening?
I don't know if the fuel pressure went low but I don't think any gauge was in the red at the time.
drseti wrote:Since you were practicing approach to emergency landings, I assume the engine was idling (perhaps for a prolonged time). If relative humidity was high, you could have picked up some carb ice. Suggest you pull on carb heat before attempting prolonged glides.
It wasn't idling any longer than when I do pattern work. There was no humidity here (California central valley)
Here's a video of a friend of mine experiencing carb icing over the central valley in May while on an instrument lesson in a 172 - it completely caught him by surprise:
It didn't fit any of the symptoms of carb icing at all. One of the times it happened it had been at WOT for several minutes with an OAT of nearly 110 F and extremely low relative humidity. It was extremely sudden, as if I turned off one side of ignition and pulled the throttle 1/4 back. Another time it happened it only lasted for a few seconds then went back to normal. And also Rotax carbs are very difficult to ice up because the carbs run much hotter than Continentals. Some LSAs don't even have a carb heat knob because of that.