2015 350MAG MPI ECT - Single Point Drain - Exhaust Manifold Drain Question

[kj68135]

Upgraded from a 4.3 TKS to a 350MAG MPI with ECT and Single Point Drain engine this year.

I'd winterized the 4.3 TKS by pulling the 5 blue plugs -- 2 on the block, 2 on the exhaust manifolds, and the one on the lower front of the engine.. Would then use a small screwdriver or wire to ensure no sediment was clogging the drain holes.

On this new engine, I see where the engine quick disconnects are at, but on the Exhaust manifolds there's a different setup..

Of course, the Mercruiser manual seems to say to just use the Single Point Drain. It doesn't go thru removing the hoses to probe for blockages.

On the Exhaust Manifold drain point, It appears there's a slot for you to put a screwdriver into and maybe pop the lower part off. I also figure you could probably loosen the hose clamps and remove the hoses too, and the water would drain.

Has anyone popped the drain piece off, and had luck being able to get it to snap back on?

Or, do you just pull the hoses?

Thanks!

 

[stikboyy]

Dont try to pop the plastic pieces apart as you will have to replace them. From my experience Mercury made these drain elbows with a large enough inside diameter that 99% of the time blockages aren't an issue and the single point drain is sufficient.(the block drains are a different story - constantly plugging).Depending on what type of water you boat in it may be a good idea to be on the safe side and just pull the hoses off and probe the fittings.

 

[alldodge]

The single point drain IF (the big if) it works correctly you just pull the bottom drain and open the vent on the thermostat housing and it all drains out. Some come with a hand air pump which gets attached to the thermostat housing and helps expel all the water.

The problem is, IF any of the small drain lines don't drain your buying a motor in the spring. Only way to know for sure it drained is pull the hose off and probe up inside as with the 7 point drain. There has already been a few threads here which have needed new motors.

 

[kj68135]

Thanks for the replies. I boat in only fresh water.

Not going to trust the single-point drain system - I want to see with my own eyes that each side of the block as well as the exhaust manifolds have drained.

 

[Bt Doctur]

At the end of the 2016 season I removed the quick crack systems from 2 boats. Both block drain brass fittings were clogged and the check ball for lack of a better term was solidly stuck in the drain port of the manifold hose, so only 1 manifold would have drained and 1 would have cracked.
Do yourself a big favor and remove the system completely and install brass drain plugs in the block and drain fittings with the blue drain plug in the manifolds. Remove the coupling hose manifold and replace with copper tubing or remove the 4 hoses and cap the ends.
For that water distribution housing with the blue plug that WILL CRACK, you can replace that with some copper fitting and a drain plug in the bottom.

 

[Bt Doctur]

 

[QBhoy]

Hi
The drain points are easily taken off and replaced on my mpi.

 

[Leardriver]

I have used an air compressor blower nozzle and stuck it into the single point drain and blasted air. You can hear it circulating air and remaining drops of water throughout the system, and a blockage would become apparent.

 

[theBrownskull]

Just pull off the hose by removing the bottom clamp. Mine has the same set up and I am thinking of just getting rid of it. It was designed originally to prolong cold water boating but all I see are more things to go bad. I have found over the summer I periodically release the quick release fitting off of the block and other hoses and see if water comes out in a good stream. It has so far.

 

[kj68135]

Thanks for all the info. Definitely sounds like getting rid of the system is probably best.