Have the same problem as yourself.
When you land, immediatly lean the mixture as far as possible for your taxi back. When you have stopped, increase MAP to about 3/4 power for 20 seconds then pull the mixture back quickly.
On restart, do not touch the fuel pump OR mixture and have your throttle nearly full open. Keep cranking until the engine starts going then slowly pull the throttle back and put the mixture in to about 3/4.
Worth a Try......