60* 150 getting water in cylinder

[mn808gade]

local guy comes in today.has 1992 150 eagle motor(60 degree block) mod -150glenc.lost #1 cyl.he rebuilt with new #1 sleeve,6pistons ,#1 new rod.had machine work done at reputable shop in Wisconsin.had block and heads surfaced flat.says they pressure tested head but still gets water into #1 cylinder.he thought water was coming in at thermostat area,and has some prob with thermostat seal.says it calls for HARD plastic seal but they used thicker/softer black rubber type and ended up cutting the soft one in half.I have not seen motor myself but it will be in on Saturday.my plan was to remove therm/and seal,and then run motor and inspect for water.thought maybe Racer or John Tiger or anyone else, could lend me their thoughts. thanx for all upcoming replys.-th

[seahorse]

Remove the voltage regulator and look down at the casting for #1 cylinder for any seam openings, cracks, or pinholes.