pressure control valve

[ltjones2004]

Hi All, My BWSeacat has twin 2008 60hp 4stroke Yamaha outboards that are fantastic and have been for 6 years and covering about 11000 nautical miles on 1400 hours motoring. So no complaints but I have an intermittent problem on one engine that is baffling the local dealer. SYMPTOMS - I get a very Intermittent overheat. I have an oven probe and display so I know the engine is getting hot when i get the alarm, I also see it cooling down after I SWITCH OFF AND ON AGAIN. THE ENGINE COOLS DOWN AND RUNS FINE. This may happen twice in a row but then is fine. Twice it has alarmed at tickover after a short run from moorings to pickup point and then fixed itself. Sometimes it will occur as I slow down to idle after a 40 minute 4800rpm run. We have changed the sensor, thermostats, water pump kit and had the head inspected which was reported to be like new. After lots of reading and three liftouts I reckon its my Pressure Control Valve. Is this likely to be the case? And if so whee is this device on my engine? I will then take any info to my trusted dealer to discuss further and hopefully resolve.

[99yam40]

I also see it cooling down after I SWITCH OFF AND ON AGAIN. THE ENGINE COOLS DOWN AND RUNS FINE.

How long does it take to cool down?

Maybe you have something moving around inside blocking passages from time to time.
Have you ran in shallow water picking up sand or shell?
Have you had a water pump lose any vanes from impeller in the past?

could the internal anodes have come apart


Which of these 60s is yours http://www.boats.net/parts/search/Ya...ter/parts.html

[arny]

Have seen once that the internal anode has broke,and blocked water outlet behind the exhaust-cover.Cover needs to be removed,and perhaps new gaskets.

[rodbolt17]

I am with arny.
I recently did one for a close friend that all 4 of the internal head anodes broke off and the internal anode in the cover broke off and plugged the water outlet like a bath tub stopper.
look at the parts diagram, I don't think that model used a pressure control valve.

[ltjones2004]

Well we appear to have resolve the issue by swapping the legs over. No alarms now and have to assume that the water pump never put enough pressure into the head for that engine but is adequate for the other. Weird but after about 4 hours motoring all seems well now!