stop......
to winterize your boat - read the factory manual
the manual states
warm engine up
change oil and filter
drain all water (manifolds, block, intake manifold, hoses)
you are now winterized
it also goes on to state you should pull the drive for inspection, etc.
now a side bar note in the manual does state the following: optional, for long-term storage, antifreeze may be added with a funnel at the thermostat housing
nowhere in the manual does it say to attempt to suck up antifreeze. because that system can not work unless you drained everything prior because the thermostat will slam shut the moment cooler water or AF hits it and it will simply go out the exhaust.
the process of attempting to suck up antifreeze from muffs only does 2 things. it spends $28 of your money in the fall to buy the kit that doesnt work. not to mention about $65 worth of antifreeze that has now run out your exhaust, yet never made it to the motor
it spends thousands of dollars in the spring to replace your motor because it froze and busted. and no, your insurance does not cover improperly winterized freeze damage.