De-Carb & Gear lube Q's

Mikefc626

Cadet
Joined
Oct 31, 2008
Messages
7
The boat:
2005 Searay 185Sport -- 4.3L MCM Alpha 1 drive (v6)

I want to do this from the FAQ (posted by roscoe):
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Decarbing is a 2 part process. The first part is preventative, done by using a fuel additive to prevent carbon build up. SeaFoam is one such fuel additive and can be found at most auto parts stores. It also works as a fuel system cleaner and should be used as a preventative maintenance procedure.If Your intent is to REMOVE the existing carbon buildup from the cylinders, heads, and rings, a spray decarb solvent product, such as SeaFoam Deep Creep, Power Tune, or Ring Free, is needed to do the decarb process. Free moving rings are what seals your cylinders and gives you compression. Compressed and stuck rings means loss of compression, broken rings, damaged pistons and heads, and eventually, engine failure.Run engine at fast idle, with engine running and warm, slowly spray liberal amount into each carb. Its gonna smoke up the place. Spray for a couple minutes, now spray a larger amount into the carb(s) until engine chokes out and stops.Remove spark plugs and spray the decarb product liberally into each cylinder, install the spark plugs, let it soak for an hour or more. Start the engine and run at medium throttle, or if at the lake, run it at full throttle. It won't hurt to spray some more through the carbs. Run it for atleast 10 minutes to flush the crud out of your engine. Now remove and clean, or replace the spark plugs. It works well to do the spraying, the night before you go to the lake. This way you can let it soak overnight, and run at full throttle at the lake.Don't do this in front of the garage door or the house, unless you want it covered with greasy black crud.
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Can I follow these steps exactly for a sterndrive (it appeared to be written for an outboard)?


I have a gear lube monitor in the engine bay. Last year when I winterized the boat, I took the cap off the monitor, and both lower unit plugs to drain the old lube, and then refilled it until it came out of the top plug of the lower unit. The lube in the monitor never moved, and so the lube that's in there now (as well as the tube going to the lower unit) is at least 2 years old. Should I remove it, and put the top plug back in the lower unit, then pump the lube in the very bottom until it comes out of the hose that attaches to the monitor? If the lube in the monitor is not even going down to the lower unit, then what's the point of it being there in the first place? I could leave the plug off, be on my merry way, and the monitor would tell me all is good while I shoot the grease that is actually contacting the gears out into the lake.....


Don S posted a stickied topic on winterizing. There is also one on the argument between muffs or no muffs. If I just pull the petcocks as he suggested, does that get ALL the water out, or is there some residual pockets left in there that will crack the block? What other hoses/things should I look at (such as the water pump)? I leave the petcocks out during the winter, so it seems to me that the water would just freeze on out the pipes and around the outside of the manifold, being the easiest route for the pressure to take. And what is this "traditional method" of forcing antifreeze into/throughout the block?


The boat will be stored in Alabama probably until next summer, then will likely be moved to Virginia next year.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: De-Carb & Gear lube Q's

Howdy,

Well, yes. "de-carb" is an outboard thing. (actually a 2-stroke thing) 4 stroke engines shouldn't need it.

That's not to say that some people think they need it and have done it. There's even threads and You-tube videos of people pouring water down the carbs of 4 stroke engines because they think they need it...... We collectively do a lot of unnecessary things to our engines because we think we need to.

A whole bunch of people will chime in and tell you what snake oils you have to pour in your engine to make it "happy" (some probably sing to their engines......to make them happy!)

Anyway I digress.....(we all digress)

Just do what Mercruiser suggests in your owners manual.

Gear lube tank. If it's been in there for a long time, I would pull it and flush/rinse it out with solvent (kerosene, diesel fuel, mineral spirits......not gasoline, lacquer thinner or MEK/Acetone!!!) When you take the drive off it probably wouldn't hurt to ensure that the hose is clear from the drive oil reservoir to the drive by flushing the hose too.

The oil doesn't flow very fast from the tank to the drive. It actually doesn't "flow" at all.....heat from the drive running actually pushes air in the drive up into the tank. The air slowly floats to the surface of the drive oil reservoir. Then when the drive and oil cools, it sucks the oil back into the drive. Eventually the air is purged and the drive oil level (in the drive) is correct, then it's just oil 'flowing' back and forth from the drive to the tank since oil level is right where it needs to be.

Change the engine and drive oil once a year. Winterize by draining all block and manifold drains (remove the petcocks and poke a wire in there to free rust flakes and debris) and fog the engine (the way Mercruiser suggests) using the fogging oil of your choice.

Use the money you save by not buying Seafoam to get the fogging oil.

Now I'll put on my flame proof suit!

Cheers,

Rick
 

Mikefc626

Cadet
Joined
Oct 31, 2008
Messages
7
Re: De-Carb & Gear lube Q's

I was wrong about the gear lube issue. I pulled the lower plug on the foot and let it drain for a good while, checking the monitor, which steadily decreased. I then started pumping oil back in, and saw that the gear lube monitor level had risen and the oil that was in it looked good (not blackish, but bluish green, probably some old oil left from the hose mixed in there). I was worried that the hose may have been clogged, but it doesn't appear so.

To make sure I got all my bases covered, do you guys see anything that I missed? I did:
1) Turn on engine to heat oil up. Changed oil and filter.
2) Changed lower unit lube.
3) Changed fuel filter.
4) Put basic seafoam in gas tank. Fueled up boat.
5) Turned boat on again using muffs to get the new oil, gas, and lube worked in, and to flush crud out of cooling system (I guess it's ok to leave the fuel filter w/ seafoam treated gas sitting up for the winter...)
6) After letting the engine run for a few minutes at about 1400 rpm, I began spraying fogging oil into the carb, then when can was almost empty, lowered rpm's to around 900 and dumped about 2 - 3 ounces of fogging oil in there. Engine choked.
7) Opened petcocks, waited for HOT water to drain (ouch!). Reinstalled plugs.

What I did not do:
Did not remove thermostat housing or pour antifreeze down into it.
Did not spray fogging oil into the cylinders via the spark plugs holes (the service manual I have actually didn't mention to do this).
Did not remove the Seawater Inlet Hose, and thus did not use the starter to attempt to turn over the engine slightly to purge the seawater pickup pump.
Actually, I could not figure out where the Inlet Hose was. It appears to be way up on the underside of the engine behind the fuel filter, which is next to impossible to get to.

Anything missing? I will go back and redo something if I didn't do it right. I would rather do it correctly now than have to pay and work more later.
 

sundowner205

Petty Officer 1st Class
Joined
Jun 18, 2008
Messages
213
Re: De-Carb & Gear lube Q's

The "SEAWTER INLET HOSE" as you call it, or the raw water hose, should be attached to your power steering/oil cooler which is either in the back of the engine mounted at an angle, or on one side under the exhaust manifold. If not angled, you will have to open the drain on it. That hose should connect to the thermostat housing and be a little smaller in diameter than the hoses going to the manifolds. You should disconnect that hose from the thermostat housing, as well as the large hose going to the water pump and drain them both.
 
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