Seafoam for an I/O

Chris1956

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I happened to notice Seafoam in the local auto parts store. I have heard many folks swear by it use to decarbonize outboard engines. Will it provide any benefit to my Mercuriser 4.3LX motor? I have a lot of time on it, but it runs well and has good power.
 

achris

More fish than mountain goat
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Re: Seafoam for an I/O

Chris,<br /><br />One of the risks with a de-carbonizer on older engines is that it may disturb the carbon around the oil control rings and the engine will start to burn more oil. That said, I use it on my 4.3LX regularly.<br /><br />Chris...........
 

jka

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Re: Seafoam for an I/O

Chris,<br />I used two bottles of it last year on my old 4.0 OMC.....after two tank fulls of gas...I didn't notice any difference in how the engine was performing. However, the marina and others, swear by it.<br />John
 

achris

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Re: Seafoam for an I/O

John,<br /><br />I've had some pretty impressive results on outboards, not so much on I/Os. I still use it on mine though.<br /><br />Was the product you used a 'spray through the carb' one or a 'put it in the fuel tank' one?<br /><br />Chris.........
 

Scaaty

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Re: Seafoam for an I/O

TCW-3 has such improved qualitys over the old 2-strokes oils its amazing! Very little build as compared to the old crap. But, Seafoam won't hurt 2-strokes, probably won't help 4-strokes, and I don't use either. I once year run TECHRON concentrate (not the injection cleaner) through all my boat motors(5), 2+4STK, and the Harleys (3) and the van that goes for all the parts for the above!
 

Scaaty

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Re: Seafoam for an I/O

Also curious as to how many people know what TCW stands for (yes, I do)?
 

bluewater19

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Re: Seafoam for an I/O

I put seafoam in my older bluewater. It also has the 4.3 4bbl mercruiser. I started the motor on the muffs and let it warm to operating temp and with the engine running at 2200 rpm slowly poured half a can into the carb. It smoked pretty bad. After that I quickly added the rest until it choked out the motor. I let it sit over night and then fired it up. You should have seen all the crap coming out of the exsaust! Did it run better afterward? You bet it did but that might have been the neew plugs and wires who knows. Now I just pour a can in every other tank.
 

mikecjn

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Re: Seafoam for an I/O

Robb,<br />I believe it is 'Two cycle- Water cooled'. Not 100% on the 3 though.
 

yoced

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Re: Seafoam for an I/O

NMMA puts out the two cycle water cooled spec, and this is the third such spec.
 

edfresh

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Re: Seafoam for an I/O

Chris,<br /><br />I have an '87 4.3l stern drive. Using the Seafoam spray info the carb throat two different times caused the compression on each of the six cylinders to increase by about 10-15 PSI. I expect that the rings were loosened so that they are better able to seal against the cylinder walls. I'm now using it in other 4 strokes.<br /><br />Ed Freshwater
 

jka

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Re: Seafoam for an I/O

CHRIS, <br />I dumped it in the fuel tank.
 

achris

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Re: Seafoam for an I/O

jkarch,<br /><br />Try the 'spray through the carb' type. I think you'll see an improvement.<br /><br />Chris........
 

Scaaty

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Re: Seafoam for an I/O

TCW....Two Cycle Weight, but then again a old fart told me this years ago, and ya never know about old farts! But the water cooled for W makes sense to me, but this is an oil argument in the making, so lets leave it at that.
 

Scaaty

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Re: Seafoam for an I/O

Originally posted by edfresh:<br /><br /> caused the compression on each of the six cylinders to increase by about 10-15 PSI. I expect that the rings were loosened so that they are better able to seal against the cylinder walls. I'm now using it in other 4 strokes.<br />Ed Freshwater
Ed, not to argue your results, but the more carbon in the chambers, the more compression you will get. If you remove that build-up, your compression should go down. And a short note on ring sealing...detonation-not the nuts in a can type-the detonation leading up to that part that which you can't hear, is the real culprit on charring rings. The explosion hammers heat down past the ring seal and cooks the oil and freezes the ring so it won't seal. So maybe thats what happened to your motor. Just a caution to watch the timing, and the gas we use now is just short of garbage. Just my opinion...
 

Bondo

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Re: Seafoam for an I/O

You guys can keep Throwing Money Away...........<br /><br />To Decarbonize a 4-stroke motor......<br />Use Water.........<br />It's done the Exact Same way as with the Sea-Foam down the carb throat method........<br />Only with WATER.........<br /><br />It's an OLD Mechanic's Trick............<br />When done just before a tear-down, there's No Carbon in the Chambers, on the Pistons, or on the Valves.........
 

Chris1956

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Re: Seafoam for an I/O

Thanks for all the replies. I will consider using the "spray into the carb" type Seafoam. <br /><br />I consistantly use 4 oz/10 gal TC-W3 2 cycle oil in the gasoline to keep the cast iron intake manifold from rusting away, and to provide some lubrication to the carb jets, float needle and top cylinder. Although I wonder if the burnt oil residue contributes to deposits, I dread thinking about replacing the intake manifold and trying to remove those rusty bolts.<br /><br />Thanks again for all the input.<br />PS to Bondo - I guess I would be afraid to pour water into my carb and let it sit a while to decarbonize. All I can think of is rust in the cylinders, water in the oil and hydrolock.
 

Chris1956

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Re: Seafoam for an I/O

Thanks for all the replies. I will consider using the "spray into the carb" type Seafoam. <br /><br />I consistantly use 4 oz/10 gal TC-W3 2 cycle oil in the gasoline to keep the cast iron intake manifold from rusting away, and to provide some lubrication to the carb jets, float needle and top cylinder. Although I wonder if the burnt oil residue contributes to deposits, I dread thinking about replacing the intake manifold and trying to remove those rusty bolts.<br /><br />Thanks again for all the input.<br />PS to Bondo - I guess I would be afraid to pour water into my carb and let it sit a while to decarbonize. All I can think of is rust in the cylinders, water in the oil and hydrolock.
 

achris

More fish than mountain goat
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Re: Seafoam for an I/O

Hey Bondo,<br /><br />
It's an OLD Mechanic's Trick............
Does this make you an OLD mechanic? :D <br /><br />Forgot about the water trick. Used to use it on the rally cars in the 70's and 80's. You're right, it does work well.
 

flashback

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Re: Seafoam for an I/O

Bondo, are you saying to put water in like a windex bottle and spray it in the carb? how much should you use? and will it work on an engine with MPI? sounds like sorta steam cleaning the inside..........
 
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