I have a 97 GTX that when in the water for 1st time this year ran okay for about 30 mins with some minor dips in power and surges, hit 50 mph or so then stalled. It started but then seemed to miss quite a bit and would only run about 40. I docked it for a while and then took it out again. This time it only got to about 25 and stalled. It finally bogged down and ran a whopping 9 mph for the 2 miles back home. It sounded very loud and smoked quite a bit. It also used what seemed to be a lot of fuel. The RPMs were around 3500 and the throttle was wide open. Occasionally it would surge as though it was going to perform better but only last a sec or two. Now it won't start at all...turns over but doesn't sound like it is firing. Here are my two concerns. At the end of last summer when it started this, I had one shop tell me there was corrosion on the pistons and the engine needed to be overhauled (Only has 141 hrs on it and is garage kept). The other said the engine seemed fine and that it was bad gas. I do know that the battery is having a hard time holding a charge, so I am going to replace it...but would a bad battery cause this kind of running? Also the plugs were pretty black with oil I am guessing? I think I could replace the plugs and maybe run it again for a bit but just think they will foul again if I don't figure out what's fouling them. Maybe carbs too rich? Anyone throw me a bone? Where to begin...I am new to these machines but want to learn! 
