Chi Man

Thanks Guys, sounds very plausible, will pass info onto engineer to check

Poss that the raw water inlet elbow on the outdrive has cracked off. The earlier ones were alloy and did this, later ones are plastic...

Possible raw water inlet hose partially collapsing under higher suction due to higher engine speed?

Thanks Paul, yes in Chi marina, will check this out, engineer is familiar with Volvo, he is suggesting temp alarm sensor and clean out...

Boat is a Sealine S23 2004, Kad 32, fully serviced in last 18 months, So, a bit of an issue. In January this year, took the boat out...