I bought a used plane with a DLE30. It was flown about a year-year and half. The engine has been inconsistent from the beginning. I had problems with dead stick so I changed the plug, Still had inconsistent performance. One day flew great. The next day, would lean out and dead stick. I then replaced the tank and all tubing. I also dropped the engine and pulled the carb. Removed and cleaned the filter. It was very dirty. Reassembled and retuned the needles. Flew great great first day of an IMAC. Great transition and unlimited vertical. The next day lacked power and dead sticked.. Very frustrating. I do not have a lot of experience with a gas engines. Any suggestions? Replace or rebuild the carb? Tear the engine down and inspect the head? Thanks in advance.