Asked by: Yuhua Krax
automotive road side assistance

Where are the drain plugs on a 7.4 MerCruiser?

Last Updated: 1st April, 2020

21
Re: 7.4 mercruiser drain plugs
Two on the block, port and starboard sides. There's also a drain on the "Cool Fuel" system, port side down around the bottom of the block towards the stern.

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In this way, where is the engine block drain plug?

The drain will be located on the rear of the block, near the bottom but not level with the oil pan. Typically they are located closer to the flywheel housing then the outside of the engine pan and will look like large bolts set into the block which are not holding anything in place.

Additionally, how do you flush an engine block? The basic steps to flush a car engine block are:

  1. Remove the lower radiator hose and catch the draining coolant in a bucket.
  2. Remove the top radiator hose and flush the system out with a normal hose.
  3. Continue until the water runs clear out of the bottom of the engine.
  4. Refill with coolant and reattach the radiator hoses.

In this way, where are the drain plugs on a 4.3 Mercruiser?

Locate the two blue drain plugs attached to it, one on the starboard and one on the port side. If you face the motor, one will be on the lower-right side of the block about midway back. The other will be on the left side of the block behind the front motor mount.

How do you get water out of an engine?

First, drain the fuel tank, fuel lines, and the oil. While it's draining, put a fan on the wiring and dry it out. Remove and clean the carburetor. Take the plugs out of the engine and turn the motor over to force any water in the cylinder out.

Related Question Answers

Abderhim Bilbatua

Professional

How do you get all the coolant out of a block?

  1. Drain the radiator.
  2. Remove the lower radiator hose, let the coolant drain then reconnect.
  3. Remove the thermostat.
  4. Disconnect the upper radiator hose from the radiator.
  5. Start the engine and let it run for 4-5 seconds OR disconnect the fuel pump relay and crank the engine to move water out of the block.

Abdelfetah Caldera

Explainer

Where is my coolant drain plug?

A radiator drain petcock is usually located above the bottom of the radiator. So even if you can open it, you're not draining the radiator completely. That's why shops always remove the lower radiator hose. That drains the entire radiator AND most of the coolant from the engine.

Mahdia Olivie

Explainer

How long can radiator flush be left in?

Let your engine idle with the radiator flush inside for at least 10 minutes, but time and weather permitting run your vehicle for 3-6 hours with the radiator flush and water solution in your cooling system.

Yumara Melendrez

Pundit

Where are the drain plugs on a 5.0 Mercruiser?

Re: Mercruiser 5.0 water drain plugs
One under each manifold, one on each side of the engine block and one in the front of the engine below the water pump. Mine are blue plastic "thumb" screws.

Sulamita Winkelheide

Teacher

How do you winterize a boat?

How to Winterize Different Boat Engines
  1. Fog the engine.
  2. Change the oil.
  3. Fill the engine block with antifreeze.
  4. Top off the fuel tank and stabilize the fuel.
  5. Drain the freshwater tank and water lines and protect them with antifreeze.
  6. Sanitation Systems.

Margaretta Abrakhimov

Teacher

How do you winterize a Mercury inboard boat motor?

How to Fully Winterize Inboard Boat Motors in 4 Steps
  1. Prepare Your Inboard Boat Motor for Winterizing. Fill the tank with gas.
  2. Add Antifreeze and Spraying Fogging Oils. After your motor is cleaned and prepared as described above, the first real winterization step is applying antifreeze.
  3. Change the Engine's Oil and Replace Oil Filter.
  4. Do a Final Inspection.

Rosely Silveira

Teacher

How do you winterize a closed cooling system on a boat?

Shut down and replace the oil, filter and fuel filter. Fully drain the raw-water side of a closed-cooled engine, including the manifolds, seawater pump and heat exchanger. Drain-plug locations vary by engine, so check your manual. Disconnect the raw-water inlet hose, then remove the drain plugs.

Icram Leiva

Reviewer

How do I winterize my sterndrive?

Here are the other key steps to winterizing a sterndrive.
  1. Drain Residual Water. First, run the engine on a flusher and get it up to operating temperature so that the thermostat opens.
  2. Fill with Antifreeze Solution.
  3. Drain/Replace Gear Lube.
  4. Check the Prop Shaft.
  5. Inspect Everything.

Kanwal Attard

Reviewer

How much antifreeze is needed to winterize a boat?

To winterize the engine with antifreeze, you'll need a five-gallon bucket, and enough antifreeze for your engine and related plumbing (at least two gallons). If your engine takes a lot of antifreeze, you might also need a helper to add antifreeze to the bucket as needed.

Lloyd Viola

Reviewer

How much does it cost to winterize a boat?

The Cost of Paying to Have Your Boat Winterized
As noted above, the average cost of having a professional winterize your boat for you is about $300.

Smahane Tsalko

Supporter

How do you winterize a 3.0 Mercruiser engine?

How to Winterize a Mercruiser 3.0
  1. Determine the amount of fuel you have stored in your tank by turning the key to the accessory position.
  2. Pour the proper amount of fuel stabilizer into the fuel tank by referring to the chart on the bottle.
  3. Remove the drain plug with a 9/16-inch wrench.

Hajira Boyanov

Beginner

How do you fog an engine?

Fog intake — diesel engines only
Spray fogging oil into the intake manifold and turn the engine over slowly by hand to draw the oil into the cylinders and spread it. Do not use the starter, even with the stop control pulled out; the engine can start on the fogging oil.

Sampedro Erneta

Beginner

What happens if you don't winterize your boat?

If You Don't Winterize Your Boat, Here's What Happens. Water freezes and expands and can damage anything it's trapped inside. Water may seep into unprotected spaces to do this. Acidic and corrosive wastes, salt and corrosion buildup can damage delicate parts in engines.

Isra Amzehnhoff

Beginner

Can I use RV antifreeze in my boat engine?

In addition to providing protection against freeze damage, some antifreeze can also be used as a coolant for running engines. Due to its slightly lower cost, some boaters prefer to use our Seafit Brand Marine and RV Water System Antifreeze, which is a propylene glycol/alcohol blend.

Eliodora Brunnthaler

Beginner

What is the difference between RV antifreeze and marine antifreeze?

Most RVers are savvy enough to know there's a huge difference between RV antifreeze and automotive antifreeze. RV antifreeze is non-toxic and meant for pumping into the plumbing system. Automotive antifreeze is a whole different critter. Many types are toxic, and should only be put into an engine cooling system.

Maiol Krausshaar

Beginner

Do you need to run antifreeze through outboard motor?

RE: Do you need antifreeze in an outboard? No need to. Keep the motor in the full down position and all the water will drain out. Keep it that way all winter so water does not get in behind the prop and freeze.

Anuta Stallbaum

Beginner

Do outboards need to be winterized?

Four-stroke outboards have a plastic air intake that you spray the fogging oil into. Fuel stabilizer in a size to treat your fuel tanks. Fogging oil in a spray can. Get the kind with a maintenance valve fitting if you have a Johnson or Evinrude outboard, 1990 and newer, with a maintenance valve.

Zaneta Godeker

Beginner

Will my boat engine freeze?

If you have an engine that is raw water cooled in freshwater from like a lake or a river and water is left in your lines, then the temperature would have to fall below 32 degrees Fahrenheit for several hours. A boat left in the water overnight should be okay. The surrounding water will keep it from freezing.