View Full Version : Engine Temp Climbs to 200F after Plane to Idle Transisition

Keep'r Wet
03-22-2011, 09:12 PM
Engines run within temp under all RPM and Load Ranges, never going above 175F. But when I slow the boat from plane at say 3500 RPM to Idle, Temps jump up around 200F to 205F and set off 200F Temp Alarm. I'm assuming this is because the belt driven water pumps slow down when the engine slows and the high heat generated from the Higher RPM cannot be expelled quick enough. But is there another issue? This shouldn't happen. What Can I do to fix???



03-22-2011, 10:00 PM
Are the engines fresh water cooled (heat exchanger and coolant) or raw water cooled (sea water system only)?

Keep'r Wet
03-22-2011, 10:51 PM
The block and exhaust manifolds are freshwater cooled and the exhaust risers and heat exchanger are Raw water cooled.

03-23-2011, 08:56 AM
Have you removed the end caps on your exchanger to see if the need to be serviced?

Keep'r Wet
03-23-2011, 09:47 AM
Heat Exhangers were recently cleaned/boiled out and checking inlet an outlet temps with a temp probe they show to be working perfectly as far as temp differential they are rated for.

03-24-2011, 01:13 AM
well sounds like a weak water pump or bad housing

03-24-2011, 01:22 AM

03-24-2011, 01:25 PM
I'd also think the exhaust elbows are partially restricted.