My poulin pro rider starts and runs fine until I engage the bade or shift to move and release clutch it just stalls out, any ideas

Check your safety switchs. It could be ones is hanging up and when you try to engauge the blade it will turn off. Most modern mowers (from 10-15 years ago) had switchs to prevent the mower from being engaiged when in reverse. Too many people were turning them over when trying to back out of things.