overheating mercruiser 228

[bill at the butte]

my mercruiser 228 has developed an interesting problem ..... took boat in for tune up and servicing when i got the boat back it started overheating if i run it over 4000 rpm ........ took it in today to have it checked and they couldn't get it to overheat ....... put it back in the water and it's heating up again ..... the mechanic that worked on the boat has been in business for a long time and seems to know his stuff ...... any ideas ?

 

[merkel54]

Overheating

Did anything get added that could be causing a cavitation near the water intake? The only other thing I can think of, and it might not apply to your motor, is that the mechanic might have the advance set wrong for over 4000 RPM. Just some thoughts, hope they help.

 

[Mike]

over heating 26 footer

my 76 24ft sedan bridge was over heating and it was bubbles coming off my transduser because of the angle it was on. my mechanic took the wedge out of the mount and it was fine.

 

[ElectEngr51]

Overheating Mercuriser 228

I have the same engine in my 1985 V-195 Sea Ray Monaco. My temp gauge with the engine fully warmed up initially read 50% of full span, but has read about 25% of full span for about the last 10 years of my 18 year ownership of the boat. That being said, is your engine REALLY overheating? Does it feel hot to the touch when it's operated above 4000 RPM...the thermostat controls the engine temperature to 160 degrees F. It may just be a bad temperature sending unit. Also make sure the negative ground cable is securely connected...if this loosens up, it will give your instrumentation the fits. If your engine is actually overheating (very hot to the touch), I suggest your mechanic check your engine's ignition timing. If the spark timing is set for too much advance, it will overheat (and sometiimes ping due to preignition) under heavy load. Good luck.

 

[top*prop]

i have had this happen to me, several times... with no explanation. it is very strange and have actually talke to mercruiser about it. they suggested i try high speed pickups on the outdrive. these are an actual part that is manufaured by mercruiser. i installed them and everything worked great.
i dont like rigging things myself but this was one time that i just had to!!!!!!!!!!!!!!!!!!