 95 explorer low compression in one cylinder
i was towing my boat over the weekend and halfway to my destination my car started to run rough. When i got home i checked each cylinder to see if it was firing and the #2 cyclinder did not change the motors performance when i disconnected the plug wire. I took the plug out to find out it was melted. I bought a new plug and put it in to find out it did not help at all but did check for spark and it was working fine. Idles rough but when i get the car over 2500 rpm it runs fine or you dont notice the vibrartion of the motor.
I checked the compression in the cyclinder and when i stated the car the compression was 90psi then dropped to 35psi. Any idea what to start with in the diagnosis? | 
