they have pics on the site. I broke my spring and had to go to a parts store, buy a package of assorted carb throttle springs. zip tie one end to the throttle arm, where the servo cable meets the throttle and then zip tie the other to a secure non movable location. adjust tension when you get on the water. IF you have it too tight then the boat will slow down as much as it is speeding up now.
You can also order one from PP. they will most likely give you one but you have to pay the shipping for FED EX.