Engine cut-out
 

I just got my first scratch built plane up and flying it was a Dazzler. I had one successful flight then on the second flight I started to do maneuvers and the motor cut-out. I believe it was caused from the pick up in the tank not getting to the fuel. The plane was doing a loop then an aileron role, leveled out made a left turn, sputtered then cut out. The motor was a .40 LA the tank was 6 oz. Is that the reason and if it is how do I fix it, if not the reason what could it be. I also have a external fuel filler in the line up. Thank you, E

RE: Engine cut-out
 

A 6oz tank is pretty small for a .40. Probably limited to about 6 minutes WOT. How long into that second flight were you? It's very easy to fuel starve an engine once the tank is below about 1/3rd full.

Barring that, there's nowhere near enough info here to really answer your question. It could be that the engine is tuned too lean, and just quit Be sure to richen the engine about 400 rpm off peak. It could be that the clunk isn't free to move around the tank (if the clunk line is too long, it can hang up in a tank corner). Be sure the clunk is about 1/2" ahead of the back of the tank. It could be that you're using too big a prop and the engine overheated. Could be a million things.

What prop, fuel are you using? What plug? Is the engine new or well run in, or almost worn out? What RPM's does it turn static, and how far off peak do you tune? What's your experience tuning glow engines?

More info and we may find the answer!

J

RE: Engine cut-out
 

The prop is a 10x6, the fuel is 15% omega, the motor is fairly new, but broken in and the plug is new. The tank was 1/2 full at the time of cut off. The plane is a great planes, dazzler weighing 3.5-4 lbs and a 48" wing span. The kit called for this size tank, but as you said about the clunk being on too long of a line I check and it is tied up in the corner and is not 1/2" from the end of the tank. I havn't checked the motors RPM when turning static but in the manual its range is 2,000 to 16,000 RPM. When I tuned the engine I started at 1.5 turns from close as specified in manual to is peak, but then turned back so it was leaned out. When I turned forward to richen the motor it would cut, I may have gone past 400 rpm off peak though, so thats why I turned back to leaner. It seemed to be running better when I did that, at that mixture I pinched the line and let go the motor revved up and came down nicely, I also revved up with throttle and held the plane straight up and it sustained its idle. I then did my first flight which was successful, landed then took my second flight were it cut out, but didnt not check or change idle in between flights. Thank you, E

RE: Engine cut-out
 

You actually have to install (and tighten) the completed stopper assembly, with fuel pick-up line & clunk, a few times to get it right. Clunk MUST swing clear of tank bottom, without getting hung up at all.

Tubing should be free of kinks, and tubing ends worked smooth/free of any burrs. A (smoking)pipe cleaner fits/cleans tubing well. Hope this helps!
ps: Dont start smoking just to get the cleaners! ;)