KAD 300 overheating

[nacho2009]

I have a 2006 Targa with KADs 300 with 140 hours, recently serviced and drives cleaned up. I have recently suffered 2 cases of overheating in the stareboard engine at medium revs (2500rpm). As soon as I notice temp is getting high, I immediately cut off power and wait until temp gets to normal level. Then re-start and engine works perfectly well. My local service is struggling to find where is problem and suggest I may have got some plastic bag at sea preventing water inflow. I think 2 times in 4 days at sea is too much of a chance and there must be some reason for this bad function. Any guidance would be highly appreciated.

 

[DavidJ]

Stuck thermostat comes to mind, cheap to replace so worth a go.

 

[Peanuts]

"My local service is struggling to find where is problem and suggest I may have got some plastic bag at sea preventing water inflow."

So why not raise the outdrive and visually check the intakes on the lower gearbox? However as you mention it is not happening everytime so I doubt it is say a plastic bag but it doesn't cost anything to check.

I once sorted out a boat with overheating issues, that turned out to be a length of poly sheet wrapped around the lower unit blocking the intakes but not the round hole at the front that allowed a limited flow through the engine. Up to that point they had changed the impeller, thermostats and even removed the exhaust manifold! As I always say go for basics and start at the beginning.

Good luck and let us know how you get on.

 

[nacho2009]

Thanks for your answers. I already visually checked the intakes and now there is nothing stopping water inflow. My local services was in fact suggesting some plastic bag sucked by the engine, and released when engine stops and water inflow decreases. My point is that I have suffered the heating twice in 4 consecutive days at sea, and never before. 2 plastics bags in 2 days is too much of a coincidence IMHO. Forgot to mention: impellers were replaced 12 months (70 engine hours) and the overheating happens suddendly, i.e. very quick and sharp increase of temp

 

[Philiz]

Raw water strainer blocked?