DLE 30 dies when fuselage pointed vertical on ground
 

Title pretty much says it all. This motor is a couple of years old. Always ran great until recently when several old hands suggested replacing the carb when the motor started acting erraticly and nobody could get it tuned to run reliably.

I replaced the carb with a genuine Walbro. After that it was all tuned up it flew fine (Velox) for a bunch of flights but then dead-sticked when in level flight.

On the ground it ran fine. However, when holding it straight up it died almost immediately. There are no air leaks in any of the plumbing.

Any ideas or suggestions?

Plugged internal filter/screen. The screen is under the cover with a single screw. Are you using an inline filter?

Thanks for the quick suggestions.

Forgot to mention that I did check the screen and there was nothing there. I did not have an in-line filter but will add that.

Question - if there was something on the screen why would the motor run perfectly normally when level but immediately die when vertical? I am a newbie with gas engine problems BTW.

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When you're nose up you're pumping fuel uphill. If the diaphragm is shot or holed that will show it. It also shows if you're tuned overly lean. Try backing off (counter-clockwise) the Low needle 1/8th of a turn. The fact you're dead-sticking in level flight could also show you're overly lean. Especially if it runs otherwise well and then just stops suddenly. Too rich usually runs poorly . . . but runs. Gently tighten the HighSpeed needle and try backing it off two turns. 1-1/2 to 2 turns is the "factory reset" for the high speed setting.

Charlie P

I'll try making the low end a bit richer the next time the temperature here goes above 40! The carb is brand new.

Could it be clunked?

IE the clunk doubled over forward.

That would do it.

Think Charlie is onto the problem...

Fuel tank was full when it stopped on the ground. I have one of those clear plastic tanks and can see the clunk is OK. Tank is a 4titude nad the internal fuel line is pretty in flexible.

split in the fuel tube inside the tank
where it meets the stopper.

Jenny

Can you see the fuel line going to the engine? Any bubbles would indicate a damaged line. It's pretty common to damage the clunk line at the stopper when assembling the fuel tank if you didn't put a smooth radius on the edge of the tubing. That would cause the problem you are describing. Less likely is a bad pump or diaphram (yes, it's possible but not likely with a new engine), some dirt causing the cover over the fuel pump not to seal properly (easy to check and fix) or the pop off pressure not set properly. I had an issue with the latter with my Zenoah. It would run on the ground just fine, would idle for days, ran with the nose up and nose down, but would dead stick after a couple minutes of flying. I was lucky enough to have a bona fide 2 stroke engine guru in the club, a really nerdy former semi-pro race driver who had started out with 2 stroke go carts and graduated to sports cars later. He even raced against Jamie McMurray at one point in his career when McMurray was 15 or so. He now owns a car restoration business that receives work from all over the world, so when he talks about engines I listen. He explained the importance of pop off pressure to me and showed me how to test it and set it properly. The engine runs like a top now, so it would be worth checking on yours too if the fuel line idea doesn't reveal anything.