I JUST BOUGHT A BOAT WITH A 2001 80 HP YAMAHA FOUR STROKE 2001 ON IT IT SUPPOSEDLY HAD ONLY 20 HOURS ON IT IT LOOKS LIKE IT JUST CAME OUT OF THE SHOWROOM,SO MUCH FOR LOOKS. I TOOK A COMPRESSION CHECK AND IT WAS NOT GOOD. #1 110 LBS #2 75 LBS #3 55 LBS #4 80 LBS. IM NOT SURE MY COMPRESSION GUAGE IS ANY GOOD. WISHFUL THINKING; ANYWAY HAS ANYONE HAD ANY TROUBLE WITH MOTOR,HEAD GASKETS PISTONS OR ANY THING THAT WOULD GIVE ME THESE READINGS/ THANKS GUOD69