Zetor 5245 Clutch Problem

I recently bought a 5245 tractor that had a clutch problem.We have since stripped it down and discovered the previous owner had fitted a clutch plate back to front!
We replaced the clutch and damaged bearing,once reassembled it turned over quickly and fired ran for approx 15 seconds and stopped twice and now wont start again,the starter tries but gets red hot and it seems like the engine is under load,if you try to start it in gear with the clutch pressed it seems like it is trying to drive!
Tried another battery and starter etc... Any ideas?

checked the clutch adjustments ?? you can adjust the pressure fingers from a hatch on the side of the bellhousing.