496 mag preventive maintenance
 

Hi There

i just bought a boat from a guy i know. It's a 2006 496 mag with 375 hours. This is a freshwater boat and nothing has been done to the antifreeze side of the cooling system. This is the first boat i have owned with a semi closed cooling system. I was wondering if you recommend cleaning the cooler or doing anything to the cooling system as far as maintenance that may be due? I have read some things about the heat exchanger end cap seals delaminating? Time for a thermostat? Or do i leave it alone???

thanks for your time!

Brian

If it were mine...

1) Drain & replace the antifreeze from the system. The AF is only good for 7-8 seasons MAX. Once it starts to turn dark, it is silting up and not flowing/cooling as well. You have to remove two small allen-hex block drains to drain it. They are not the easiest to get to on a twin application, but a single should be fine.

2) Remove the heat exchanger completely, and then remove the end caps and clean out everything. Be careful, as the tubes are fragile. Replace the end cap gaskets. And replace the grommets which go into the crossover. Both of these items DO go bad.

Contact member "BUP" if you have any questions. He is a Merc dealer, and can source all the gaskets and grommets for you.

thank you very much for the advise. I ordered everything to remove and clean cooler. And replace t stat as well.

Change the coolant but I think I would leave all else factory sealed.

X2