aj1985

I have a 2011 mule 610. I changed the motor and removed primary clutch from the old motor so that i could install the new one. I installed it on the new engine and adjusted it back to where it was on the old motor. But when i take off the clutch adjusts itself all the way back against the belt. The clutch threads onto the shaft of the pulley that sits on the engine crank.the clutch moves on the threads and doesnt stay adjusted. The mule will move but really slow. Any help would be appreciated.