Hello, I'm trying to assist a friend. He has an older (7-10 years old) 14.5 Briggs i/c MTD 42" that won't continue to run/idle. It starts with gas/starter fluid, but dies after word very quickly. I took a compression test and it's holding at 90LBS. When it does start, it does not smoke. We swapped out two different carbs. Cleaning both and soaking them in carb dip for 48 hours. Rebuilt and installed. Again, it will only start with assist from starting fluid or splash of gas. Now here is the tricky part, on a hunch i shoved a rag in the breathway of the air cleaner. Really restricting the airflow. Much more so that the choke does, but still allowing some air to pass. Bingo It will run like that. Accually runs pretty well too. I can actually get it to almost idle. I checked for vacuum leaks or cracks on the intake (this one is aluminum) and I can't locate any.. Any ideas?