1982 Merc 470 Circulating Pump Drain Plug

[wrestling coach]

Just getting my '82 Merc 470 ready for the new season and I was starting with fresh 50/50 mix of new coolant. The boat has not run since last October. I started by removing the circulating pump 3/8" brass drain plug and I expected to get at least a small amount of coolant to drain. Nothing. Not any sign of coolant. Dry as a bone. Got a small piece of wire and tried to probe and find some debris but I can't get that wire in past the depth of the plug. It just seems like a solid bottom. Am I missing something here? What size hole should I be finding?

Dennis

 

[Bt Doctur]

Re: 1982 Merc 470 Circulating Pump Drain Plug

on;y 3 drains. stbd side of block in the rear corner ,heat exchanger and here

 

[wrestling coach]

Re: 1982 Merc 470 Circulating Pump Drain Plug

on;y 3 drains. stbd side of block in the rear corner ,heat exchanger and here

Yes. I know of the 3 drain plugs. But when I removed "a" in the picture above I found no coolant draining at all. That would be my question. Shouldn't I have had some flow of coolant when I removed that plug?

 

[wrestling coach]

Re: 1982 Merc 470 Circulating Pump Drain Plug

ttt