It may just need tuning. But a couple days ago I was BS'ing with the guys at the field and we discovered that all 3 of us had to replace the carburetor on our DLE engines to get them to run properly. One was a DLE-20 and two were DLE-30's. All three of us bought exact replacement DLE carbs. As the original poster of this thread, I now have about 14 gallons of fuel through my DLE-30 and not one single dead stick since I replaced the carb. YMMV, but that's my story.
I believe you may be right....I spent a considerable amount of time at the field last week with the DLE 30 trying to get it to fly inverted without cutting out or acting up - no luck.
I bought the motor used so have no idea how old it is, I've owned it for 2 years and only recently have had problems with it; the original carb was a DLE carb.
I purchased a new Walboro carb from Tower Hobbies and installed it along with re-building the tank. I found that the 6 month old pick up line was stiff and I replaced the foam filter clunk (Fortitude tank) with a heavy metal DuBro clunk.
"My DLE35 runs the same way. I cannot seem to tune out the mid range burble without compromising reliability so I just live with it. I'm going to switch to a higher octane (90) and 40:1 to see if that may help a bit???"
AK Nick, I switched to high octane fuel, 32:1 mix of Stihl synthetic oil and re-gapped a new NGH plug to .022 - .024 a while ago and it helped eliminate some of the mid range burble - this inverted problem is recent and so severe that I dont dare fly inverted much less inverted harriers down low!
Wish me luck at the field today.
