Tech Tip with the single point drain system

[Bt Doctur]

Tech Tip with the single point drain system, be sure to remove the quick connect fittings on both sides of the block.
They do close with scale and corrosion . The same thing happens with the so-called flushing system. The block connection become closed from corrosion and will not allow it to drain properly or allow fresh water into the block to flush it.
Also ,there is no way to drain a block or manifold with this type of system.So if your thinking of just introducing it with a running engine
THINK AGAIN
My current rate to dress and replace an engine is $1600 plus the cost of the engine.You decide

 

[Bondo]

Ayuh,..... I'm with ya All the way on this BD,.....

My Tech Tip to folks with any of the Mercruiser guarantied, sure thing, frozen busted block, "Quick Drain Systems" to to strip every bit of it off the motor, 'n buy a pocket fulla brass pipe plugs,....
1/4" brass pipe plugs with the 9/16" hex-head, 'n the 1/8" brass pipe plugs with the 7/16" hex-heads,....

No matter how Clean, or crudded up water yer boatin' in,....
Sand, mud, sea-life parts, rust scale, 'n general Crud builds up the the bottom of the block's coolin' passages,...

If ya ain't pokin', Something into the 3/8" hole the 1/4" drain plug screws into, yer gonna loose a motor,...
Maybe not this year, but ya Will loose one, not pokin' the holes out,....

My favorite "Tool" for the task is a 3" ssteel deckscrew,....
The ones in my toolboxes are just plain ole coated screws, the ones that live on intake manifolds when not in use, are ssteel,...

'n always remember to pull the Big hose off the water circulatin' pump,....
It'll hold 'bout a quart of water on a V-motor, considerably less on an In-liner, but enough to freeze the pump solid,......

 

[Scott Danforth]

Also, do not forget to backflush the power steering cooler. it is generally the first "strainer" on the engine

I have a section of 3/16" polly hose with a hose end adapter that works great for shoving into the block drains for rinsing the crud out. Poking gets the water flowing for draining, however there still is about of pound of sand, rocks and the sea-life that bondo pointed to in the bottom of the block passages.

After poking, and draining, I shove the hose into the block, turn the water on full and work it back and forth forward and aft into the water jacket on both sides. usually takes a half an hour, not including the bilge cleaning needed afterword.

I bought a 25' roll of the hose, a bunch of ferruls and the hose adapter and little hose shut-off at lowes. to date, I have only used 6' of the hose.