Yamaha 15 HP 4-Stroke low compression and water in oil

[MILLSMAN]

I have a 2005 Yamaha 15 HP 4-Stroke that has low compression (85 PSI, 95 PSI) on both cylinders and the oil is milky looking. Lack of power at higher RPM's. Bad head gasket? Is this common with this motor (F15ESH)? How hard is it to replace? Need any special tools? Thanks

 

[raczekp1]

its not only head gasket. need to change
you need to bring head to machine shop for surface grinding and valves cleaning and fitting.
look int cylinder bores and look for any scores in bores