[August Rush]

The mufflers in my 4000 have no drains. I find it kind of wasteful to push 30gals of antifreeze through each engine for what should take 5. If I pull the inlet hose, will the mufflers drain enough to prevent having to fill them with antifreeze?

I have the same boat and have the same concerns about pushing 15 gallons each through the exhaust.   How would removing an inlet hose help drain them?  I think you mean remove exhaust hose?  If so, good luck reaching it...lol 

The amount of antifreeze is probably overkill.  I assume there is lots of room for expansion but it looks like it would be a nightmare to have to replace one of those mufflers so I will just keeping using antifreeze.