Hi, I own a 1980 742 Bobcat. It has a 4 cylinder Ford engine in it and has been giving me a bit of trouble lately. It runs like a top when it sits and does nothing, both at full throttle and at an idle. When you push the sticks forward is starts to run rough. It doesn't stall but has very little power. I have put in a new fuel filter, checked and cleaned the air cleaner, checked and cleaned the plugs and put gas line antifreeze in tank. I don't know what else to do on this old girl. She has been a great unit for the last 3 years that I have owned her. Can anyone give me some suggestions?