helphelphelp!

hey i own a sun dancer by pro boat i havent used in at least two years or more i recently deceided to use it so i took it out of the closent ang i was missing the controler, and battry and all the parts were unmounted i took it to the local hobby shop for the repares i got it back to day charged up the battery and took it out for a test run the boat would lunage as apose to run smothly it was stop and go near the end of the run i got it to start to run smooth i dont know wut is wrong plz help