Hi I am looking at a 1988 johson bubble back 140 hp.. Motor runs real good but has water in #3 cyl.. compression is 110-120 in all 4 cyl.. owner said he got the motor from po and he noticed the water and had changed the head gasket but never milled the head,. seller seems pretty legit demo`s motor in can plenty of water from telltale and has infared heat gun and it shows about 130-132 degrees after about five min.. does not seem to get any hotter..in or out of gear, He wants 500.00 for it but recomends to get head milled and new gasket right away has tnt works perfect and will also come with prop.. Thinking of taking a chance, anybody have any ideas? or advice?? has anybody ever run across this problem?? Thanks in advance Bill