I let the niehbor borrow my newly puchased cadilac machine (318) and now when it runs the motor wont stay at a constant speed it revs up and down constantly. The blades on the deck dont run at a constant speed now ether. I think it ether needs a new belt posibly because I turned the adjuster as tight as I could get it on the front of the machine and it aint got any more adjustment to give. I an hopping its just the belt worn out. Its the first and only tractor I have had with a electric pto and I am hoping its not the pto clutch or something. Thats the only thing I could think to be wrong with the blades but what odd it the faster i drive the machine it seems lik th blade turn faster as well but its still not cutting right and I am not giving it anymore throttle just pushing further forward on the hydrostac shifter. Am I on the right track with the mower deck thinking its just a worn out belt or are they know for something more going wrong? I am going to plobly have to take it to the dealership to get the motor to run at a steady rpm but I'd like to figure out the mower deck problem on my own and get the grass cut at least.