420 cc predator sps mud motor

Hi!... I just bought one of these and put it together ..I really like it ..but ..I can't seem to get the throttle cable to work properly... Where its supposed to go which is the big chrome peice where the turtle and rabbit are...is way to stiff to work right !.... Can't it be loosened ? Or should I hook it up to the throttle link under it which is way more responceive...? Any help is thanked in advance