Mercruiser 350 5.7L Engine

[Cmunt]

Hello all,

New boat owner. I have a 20ft Arriva with a 350hp I/O. When I pulled some plugs while winterizing last fall and can’t remember where to put them back in on the engine.

Anyone know where’s these two bolts go?

Does it go where I have the circle?

Thank you in advance.

 

[BruceK]

Raw water cooled? - put on the muffs, remove thermostat, and see where water pours out.

Coolant with heat exchanger? - fill the header tank with water and see where it pours out

Guaranteed to work every time

 

[spannerman]

Don’t run it unless you want to drown your stater motor, the plugs sit under each manifold a little over halfway back along the block.

 

[BruceK]

Ya but do you deny he would have found the holes

 

[B58]

Check your exhaust manifold gasket between the manifold and elbow, if you see rust , they can leak back into the engine.

 

[QBhoy]

The first picture is of the old type block drains. One each side low down on these. Usually the larger fitting stays in the block. The smaller male insert gets removed. I presume you found where the others go ? One each manifold at the very least. If you send a pic of the whole engine, I’d be able to tell you where all the drain points are. I’m assuming it’s a 5.7 from around ‘88-‘91, being the bayliner arriva, I presume it is. Lovely hulls on these. Fast boats and a lovely step away from the usual bayliner hull. Lovely things.