This is fantastic reply! And the only one advising to check these check valves! My other riser runs 30 degrees cooler than the other one (and also the other engine), I could almost guarantee that the check valve is malfunctioning! Thanks again!
I bought my boats with 45 hours on it and at 350 hours I have two cracked heads and water in the oil (cracked in exhaust valve seats). After inspecting the heads they don't appear to be marine heads which to my knowledge should always have steel re-enforced valve seats. Also the combustion...
