Mid 2000 TXT revs high and smokes

[brinkkl2000]

Figured I would ask before I tore the engine apart. Working on this for someone else. He brought it to me because it smokes a lot. He has 160lbs+ in each cylinder & valves were way out of adjustment. I have not done a leak down test. I have the back end up on stands to keep the transmission engaged so governor kicks in. As soon as I hit the gas, it revs up to the max. I think I saw 8000 before I shut it down. It does this if I am just off the limit switch, or to the floor. There does not seem to be any rev limiter kicking in. I will also say, as per my other post, I found that he hooked the battery up backwards after winter storage, not sure if that could fry anything or not. What should I look for as to why this is over revving, mechanical governor in the rear end doesn't seem to be working, nor the limiter in the ignitor? I did also pull the carb to check the throttle plate is not missing or stuck open, and it is not. It is smoking too, could he have over revved it and caused damage that would cause smoking?