Ive checked my manifold and riser with acetone no leaks. Ive instaled a new oem graphite gasket and im still getting water in my #3 and 5 exhaust port. Thru hull exhaust with a 15 degree slope to tips above the water line. Compression on those two cylinders is 145 160 . Is there any other way for water to be sitting in manifold and exhaust ports