I have a houseboat with two Merc 5.0L EFI's (2001 model) with Bravo II outdrives which have the seawater pumps on the engines. I have clear plastic top strainers inline from the outdrive to the pumps with shutoff valves. As I get older I find it more difficult to crawl around and manually remove the little blue wing nuts to drain each engine. Last year it was my hope to not drain the blocks. I ran the engines until they got up to temperature then shut the valves off, restarted the engines and poured antifreeze mix in the strainer until antifreeze came out he exhaust which was about 2 gal. I pulled the lower block plugs the next day and was surprised to get clear water out of the block. I then pulled all six drain plugs from each engine and then poured antifreeze mix in the thermostat "hole" until the blocks were full.
I am just curious why the blocks did not fill with antifreeze? I always thought that you needed warm the engines to get the thermostats open in order to get the stuff circulated. A friend told me that in his big block Merc EFI's with V drives, he starts his engine cold and start pouring antifreeze mix in his strainer until he gets about 4 gals run through.
Any thoughts on this would be appreciated.
Rick
I am just curious why the blocks did not fill with antifreeze? I always thought that you needed warm the engines to get the thermostats open in order to get the stuff circulated. A friend told me that in his big block Merc EFI's with V drives, he starts his engine cold and start pouring antifreeze mix in his strainer until he gets about 4 gals run through.
Any thoughts on this would be appreciated.
Rick
