I have a 1994 150 Johnson which is running about 1500 rpms lower than usaul and is very sluggish. I decided to check the compression first and all cylinders regestered between 78 to 80 Pounds of pressure. The manual did not give any numbers for compression only that their should not be any more than 15 psi between cyl. My question is does anyone know the range that the compression should run or what is considered poor compression? Thanks for any help.