Hi,<br />I bought motor with #5 bad. Bored #5 and replaced piston and rings.Ran for 30 min.before #5 went bad again.Sleeved #5 and installed new piston and rings.Also went through carb. and swapped #5 with #1 carb. and swapped heads from port to starboard.<br />I ran motor for 15 min. and rechecked compression had dropped 30 lbs.Inspection of cylinder shows that scoring has already started and the cylinder appears dryer than the others.The carb bowl is getting fuel.I need help on this one.What can I check for?