mariner 25 hp 1995 model<br /><br />When cranking motor with pull chord i get a hard catch about every third or so pull. It's so hard that if your not ready for it, it will pull the chord out of your hand and hurt like %*##. Also when starting with starter I hear the motor knock hard about every 10th revolution. I think this is the same thing i'm feeling with the pull chord. Is there a compression release on this motor and could that be going bad? What could this be?