Me and outboards...

Mar 26, 2011
3,402
Corsair F-24 MK I Deale, MD
FTR, chainsaw and weed wacker carbs are very different--no float/needle, and no free surface. Diaphragm. I've had chainsaws too, but I don't think those experiences actually transfer to marine carbs. Too many differences.
 
Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
If you did not previously, use Seafoam (or Biobor EB or Merc Stor-&Start) all of the time. <snip> The additives listed have been tested to stop corrosion in e-10 gasoline (Practical Sailor).
thinwater- Have you tested Ethanol Shield? A small engine dealer near my home who has been in the small engine service and sales business for 40+ years claims that ES is the best additive around to counter the bad effects of ethanol. He says that it is all he uses and recommends to his customers.
I currently use the Marine (green color) StaBil, but I am switching to Seafoam or Ethanol Shield (if I can confirm that it really is superior). And as I stated in a previous post on this thread, I have also switched to non-ethanol gasoline for all my small engines. Maybe with non-ethanol fuel I don't need any additive? What do you think?
 
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slooop

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Jan 29, 2015
16
Hunter 34 Panama City, FL
I have a Nissan 3.5 (Tohatsu makes it) two stroke. I always use the non-alcohol gas with Stabil added. NEVER run all the gas out of it. The smidgen of gas left will turn to varnish if you do. I've head the engine for about 10 years. Never had a problem tho sometimes a year goes by between starts. Same practice with my lawn equipment. Stabil works.
 
Jun 2, 2011
347
Hunter H33 Port Credit Harbour, ON.
I'm a little late to the conversation but figured I would throw this out. I don't deal with outboards and no longer deal with many small gas engines. Antique cars, the lawn mower and snow blower are my headaches. Before starting to use Stabil in the cars I was dealing with the issues in the carburetors of the antique cars that don't run a lot. The varnish in the carbs was hard to clean and the standard carb cleaners were ineffective. Frustrated, I poured some Kleen-Flo Diesel Fuel Conditioner into a container and threw the varnished parts into the container. (We have 200 or so diesel engines and use a lot of the Fuel conditioner) When I pulled the parts out of the fuel conditioner they were spotless. The varnish was completely gone.

So, when I fired up the lawn mower and it ran like krap I figured what the heck, poured about 3 ounces of fuel conditioner into the tank, shook it up and started the engine. 5 minutes later the lawn mower was working perfectly. Same thing happened with the snow blower. Now I toss in some fuel conditioner when I fill the gas can and never had another issue.

All of the above mentioned products work well in maintaining a working system but once it is clogged or varnished it seems to be another story. For what it's worth, the Kleen-Flo fuel conditioner seems to clean the carb in situ. I also use the fuel conditioner in the boat fuel.
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
So Jake, you are adding diesel fuel conditioner to gas engines. Is that right? I guess it would work. Don't see why it wouldn't. But I am not an expert (a little obvious because I started this thread).
 

RussC

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Sep 11, 2015
1,578
Merit 22- Oregon lakes
After 45 odd years in the outdoor power equipment business I finally came to the conclusion that some people just have a small engine curse, wile others do not. Since taking the lead out and putting the corn in, many problems have developed that were never there before, for sure, but still....... there were always regular customers of mine whom I would see with the same piece of equipment several times a year for varnished up carbs, fuel lines that were no more than a glob of melted rubber stuck to the bottom of the fuel tank, and when you took the fuel cap off, the rotten fuel smell would just about knock you over. But then there were those who NEVER had any of those issues (me for one). I was always asking questions in my attempt to find out just why some had problems but some did not, but I really can't say that I found any one conclusion. the storage conditions did seem to have an effect in many cases. equipment that was stored in a garage, rather than under a carport or under the usual chunk of plywood for example, seemed to benefit greatly from that. fuel stabilizer helped somewhat. non-alcohol fuel may have helped. draining the fuel during longer term storage always seemed a good idea. etc etc. but then again... I myself never drain fuel out, have NEVER used non-alcohol fuel, and almost never use any form of fuel stabilizer. yet just a couple weeks ago I dug my little Mantis 2 stroke cultivator out of the woodshed where it had sat since this time last year. the fuel stunk a bit, so I dumped it in the drain oil can, put in fresh fuel, cranked it up and used it for an hour or so with no problem.
One thing that I told all my customers was that the best thing you can do for your equipment is to go out and start it up for 10 minutes or so at least once a month. those that heeded that advise most certainly had fewer problems with the fuel system. also if it hasn't been run for a few months always sniff the fuel in the tank before you pull the rope. if it doesn't smell like fresh fuel than dump it and put in fresh fuel.
I never got rich in the 31 years that I owned my own shop, but maybe that was because I always tried to offer free maintenance advise. fortunately for me, many did not take it and, as I said, some just have the small engine curse. ;)
 
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Mar 26, 2011
3,402
Corsair F-24 MK I Deale, MD
thinwater- Have you tested Ethanol Shield? A small engine dealer near my home who has been in the small engine service and sales business for 40+ years claims that ES is the best additive around to counter the bad effects of ethanol. He says that it is all he uses and recommends to his customers.
I currently use the Marine (green color) StaBil, but I am switching to Seafoam or Ethanol Shield (if I can confirm that it really is superior). And as I stated in a previous post on this thread, I have also switched to non-ethanol gasoline for all my small engines. Maybe with non-ethanol fuel I don't need any additive? What do you think?
No, I have not. Stabil was consistently mediocre--I just barely consider it a preservative. Seafoam, Merc products are good, and I switched to Biobor EB five years ago, since it was best.

I would use one of the above additives anyway. EVEN with non-ethanol fuel it's not that hard to get a few drops of seawater in a dinghy outboard tank, and it's the real killer. We routinely detected measurable amounts of seawater in fuel supplies--not much, but even 20 ppm of chloride is a LOT in terms of corrosion with aluminum couple with brass in a carb. If you ever see a black freckle in the bowl, that is corrosion, and it only takes a few micrograms to clog a jet.

Practical Sailor has tested these numerous times and has worked with ASTM on developing a standard test method for both diesel and gasoline.
 
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Jun 2, 2011
347
Hunter H33 Port Credit Harbour, ON.
So Jake, you are adding diesel fuel conditioner to gas engines. Is that right? I guess it would work. Don't see why it wouldn't. But I am not an expert (a little obvious because I started this thread).
Hi Brian,

Yes, fuel conditioner in gas engines. Seem counter intuitive but when I saw how quickly and efficiently it cleaned the varnish off the carb parts I had to try it. It worked like a charm with no noticeable performance issue.
 
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Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
No, I have not. Stabil was consistently mediocre--I just barely consider it a preservative. Seafoam, Merc products are good, and I switched to Biobor EB five years ago, since it was best.
Thanks for your info.
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Since I got serious about closing off my tank vent when not in use, and adding seafoam and Biobor EB three years ago I have not had a problem but here's the thing. Carburetors by design are open to the atmosphere and fuel in the bowl is in contact with the salty sea air. The newest fuel efficient carburetors have extremely small jets and fuel passages that are easily blocked by corrosion debris. So I assume that until all outboards are built with closed fuel injection the ritual of regular carburetor replacement will continue.
 
Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
You know,, Gunni, I never even thought about the fact the carburetor is open. :yikes:
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Brian D said:
... I never even thought about the fact the carburetor is open. :yikes:
That's why I always keep my choke on when not in use. Keeps bugs out, too, I guess.
 

RussC

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Sep 11, 2015
1,578
Merit 22- Oregon lakes
That's why I always keep my choke on when not in use. Keeps bugs out, too, I guess.
Most choke plates have a hole in them to limit enrichment. the fuel bowl also has an external vent, otherwise fuel could not enter the bowl .
 
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Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Carburetion is the reason why I pull the fuel hose and run the fuel out when I will be away for the week. I figure what isn't in the carburetor can't absorb moisture. A set of 'ear muffs' helps and make it easy, flushes the salt too.
 
Feb 10, 2004
3,919
Hunter 40.5 Warwick, RI
I spoke with a friend tonight who repairs small engines for his business. We talked about various ethanol additives as well as smart operational practices and the use of canned gas and non-ethanol gas. This is a guy that not only repairs engines but operates his own trimmers, chainsaws, and a 1956 Johnson outboard.
I asked him specifically about "Kleen-Flo" Diesel Conditioner that was mentioned in an earlier post to be capable of removing varnish deposits. He had heard of it but never used it. He did tell me that there is a product called "Mechanic in a Bottle" that he has used with success on a variety of engines to clean out the carburetors. He was quick to point out that while he has had successes, there are some engine/carb conditions that are beyond the capability of any additives.
In terms of ethanol mitigating additives, he recommends (to all of his customers and uses it himself) a product called "Ethanol Shield".
But one of the things that he told me that I did not realize was that when you run a carb out of fuel, there is still a small amount left in the bottom of the bowl because the fuel pickup in the carb does not draw from the very bottom. So what he does is he opens the drain screw of the carb and drain/shakes until it is dry.
So my plan for the future is to buy non-ethanol gas from a nearby state in a quantity that I will use in my summer season. I will immediately add Biobor EB or Ethanol Shield, or Seafoam to help deal with the water. If I can find the Kleen-Flo Diesel Conditioner, I will add the recommended amount to that container of non-ethanol gasoline.
And hope for the best. I have no "Plan B".
 
Jan 25, 2011
2,391
S2 11.0A Anacortes, WA
I have a honda 2.3 OB and a honda 2000. Throw in the Generac 6.5K at home. Have had these for 5 yrs. Always use non ethanol gas and keep vents closed. Other than that, I do nothing and everything works fine. The 6.5 gets started spring and fall (haven't had any serious outages) and the others can go ~7mo over the winter without use. I'll be at the boat tomorrow and maybe I'll pull the cord on the OB. Hmm, did I just jinx myself?..