Marvel Mystery Oil

[sastanley]

Dave,

My C-30 had an anti-siphon valve halfway between the muffler & the thru-hull. As a kid I remember hearing it tick but for the last 20 years or so, it has been broken. After some research, I am removing it and adding in a 45 degree fiberglass elbow, since I already have a break in my exhaust hose in that location (came in two 10 foot sections), and need at least a coupler there.

That might avoid the back-up, if your loop is high enough to avoid siphoning in the first place. Apparently it was included in earlier C-30's, but not included in later ones. Since this one's been broken for so long (the flap was laying in the fitting), it obviously hasn't been doing anything for years. The only time (twice) this motor had seawater in it was from overcranking.

[Dave Neptune]

Stp

I just add what I believe is the pint size and I use 30wt oil as well. No problems yet!!!!!!!!!!!!!!!!!!!

Dave Neptune

[Dave Neptune]

Vented loop

Shawn, unfortunately my engine sits a-mid-ships and the loop is on my water injection side of the exhaust. Because the loop has to be so far from that point due to routing my exhaust will almost fill up from what is in the loop itself. I am using the shortest route for the vent, which is aqctually mounted in the main salon area so I can hear it break open if I remember to listen and I have a manual vent as well.

Dave

[sastanley]

Hi Dave...sorry, maybe I wasn't clear...

I also have an anti-siphon valve (similar to the one Moyer sells here) in my water injection system for the exhaust. What I meant in my previous post is the loop is simply the exhaust hose itself being lifted as high as possible above the waterline in the sail locker..at this point the 'coupler' was one of those one-way bronze flapper valves..I have chosen to replace it with a simple fiberglass coupler, since the flapper valve hasn't functioned for over 20 years.

[Don Moyer]

DVD,

Having no experience whatever with any STP product, I will have to defer to those who have.

Don

[old-sailer]

SeaFoam

After reading Don Moyer's description of MMO it appears to me to be similar to SeaFoam a product which is easily available in Canada and the US and does the same thing. I have used SeaFoam in old motorcycles and it cleans them out marvellously. Runs smoother, idles smoother etc. Maybe it would be an equivalent to MMO more readily available?????

Thoughts??

[dvd]

MMO is easily available in the US at almost any auto parts store. I have heard that it can be difficult to obtain in Canada. As to its comparison with the sea foam product I don't have any experience with it.

dvd

[CalebD]

old-sailor,
While I have not used Seafoam on my old A4 yet, it does seem to fit in the same niche as Marvel Mystery Oil so I would probably use it in the absence of MMO. They had Seafoam on the auto parts store I was in about a week ago right next to MMO in NY State.
I say use it but with the caveat that you use it according to the label's directions. It is the "foam" part of the Seafoam name that makes me wonder and since I've never used it I wouldn't know.
Don Moyer recommends using MMO as an additive to the fuel and in some cases to the oil reservoir as well. MMO is an oil, about a 3W oil and is not a foam. MMO also claims to have rust/corrosion protection additives which sounds a lot like the claims of Seafoam.
I use MMO to fog our engine come winter layup; that is, I put several good squirts into each cylinder. I will repeat this procedure as I see fit during the season to help loosen the cylinder rings, valves etc. Seafoam sounds like it should do nearly the same thing in both the fuel and lubricating systems.

http://www.seafoamsales.com/how-to-use-sea-foam-motor-treatment.html

[Carl-T705]

I swear by Seafoam, it has different use than mmo as far as a lubricant or rust preventative. I put in everything that runs or sits around idle ,lawn mowers, Onan generators,all my cars and trucks. This is the only product I have ever poured into a fuel tank or straight into the carb. and could immediately tell a difference in performance and fuel mileage. I buy it by the case. It isn't cheap but it is worth every penny.

[Ajax]

Seafoam does not "foam". It's just a name. I use it to keep fuel systems clean, and for unsticking things, but it's not a lubricant like MMO.

If I needed unsticking properties in a lubricant, I'd use MMO. If I needed unsticking and cleaning properties, I'd use Seafoam.

[old-sailer]

This is my experience and feeling re Seafoam also. I have used it in various engines and they have all run better after use.

I swear by Seafoam, it has different use than mmo as far as a lubricant or rust preventative. I put in everything that runs or sits around idle ,lawn mowers, Onan generators,all my cars and trucks. This is the only product I have ever poured into a fuel tank or straight into the carb. and could immediately tell a difference in performance and fuel mileage. I buy it by the case. It isn't cheap but it is worth every penny.

[Carl-T705]

As a note, I would more research before adding Sea Foam to an A4 crankcase. Because, I would be concerned about the effect on the clutch friction plates in the transmission. It may have an adverse effect on the surfaces .

[hanleyclifford]

Seafoam does not "foam". It's just a name. I use it to keep fuel systems clean, and for unsticking things, but it's not a lubricant like MMO.

If I needed unsticking properties in a lubricant, I'd use MMO. If I needed unsticking and cleaning properties, I'd use Seafoam.

I agree with these observations. Just to complete the picture, I see STP as a thickener, coater, and protector type of product.

[old-sailer]

I agree with these observations. Just to complete the picture, I see STP as a thickener, coater, and protector type of product.

STP is a viscosity boost. That' all it is. It will turn a any oild grade (like 10W30) into a much higher viscosity depending on how much you add to a given quantity of oil.

The general information I see from those who test oil is that it only has a benefit in really old engines that burn oil and should actually be rebuilt.

[Ball Racing]

STP may still, but used to have some additives that helped against wear, scuffing, etc. that was a bonus to add to some oils.
And I think it used to have zinc in it too,
For a while I used it as a assembly lube.