Bad vibrations

The airport opened during the week so when I got home from work mid afternoon I thought I would start up the engine and taxi around, get my air legs back, so to speak.

The engine would not start, I tried several methods and eventually left it alone for a while. Near full throttle start worked and the engine roared into life. I let it warm up and started off away from the hangar. It felt like I had three flat tires, the vibration from the engine was intense. I increased the rpms and things smoothed out, I taxied around and everything was going great so I headed back to the hangar.

Just before the hangar I brought the power back towards idle, the vibration got real bad again, the rpms dropped to 400 and the engine quit.

I pushed it back in the hangar and wondered what now?

I did some reading and decided to check out the idle mixture setting the next day with Allen