I have two DLE 35RA engines that had a similar problem. The fix was adjusting the L needle out until it ran regardless of the factory setting range. Both engines run fine and respond to needle adjustments both in temp and RPM.
The engines are in full cowls.
I have a DLE 55RA as well and I have never had any issues since new with it. Also full cowl installation. Ive made very minor adjustments since new on that carb and been an awesome engine. At around 25 flights the stock muffler broke apart so watch that. You will see a leak of black oil residue around the manifold weld before it breaks.

Maybe take a look at the reed block and sand it flat to be sure the reeds seat flat to the surface and do not leak. Then assemble and try again. Also adjust the low speed needle until it runs regardless of what you think it should be or not. If it runs at 5 turns out then thats a result. Then if it runs ok and reliable your good to go.

A Warlboro carb would be better but there are many models to choose from so you have to match it to the engine. I dont recall the model number but a quick search and comparison would answer that.