1996 115hp Johnson compression problem

[zing99]

I've got just over 100psi in 3 cylinders. Cylinder #1 upper right looking forward only has 75lbs. I'm going to pull the head on the starboard side and have a look. Problem is I have no clue what to look for, any tips are appreciated. I've never taken a compression reading so this may have been like this for a while or it may be related to my other thread bogging down @3000rpm.

 

[Daviet]

Re: 1996 115hp Johnson compression problem

Remove cylinder head, see if top of piston shows any damage. Rotate flywheel and look at cylinder walls for any deep scratches or pitting. Check cylinder head and make sure it is not warpped and mating surface on block is not damaged.