I just pulled an 8hp briggs from a simplicity rear engine. In order to mount it up I need to remove the oil drain stem. It has an odd looking nut. when I loosen it it tightens after several turns and the same in the other direction. Is this some sort of lock nut and once loose then loosen the stem? I'm hesitant to put too much torque on it, dont want it broke off. I could cut it and cap it as an alternative. Removable cap obviously.