carb flush?

[HalcyonS]

A few weeks ago I found my idling problem was due to a buildup of a yellowish paste I called 'carburetor cheese' in and around the idle air intake (and nowhere else, oddly).

The collective wisdom of the Afourians opined that it was some kind of ethanol additive buildup. If this is going to be a problem we experience increasingly, then I've been thinking we need a way to deal with it - hopefully without a full carb tear down and rebuild.

Idea 1 - partially detatch carb so a source of suction can be attached at the manifold end - ie shop vac? and pump carb cleaner in through the fuel line.
Carb cleaner fumes would probably melt the shop vac, try an all metal vacuum cleaner? - if they still exist.

Idea 2 - detach the carb and fill the throat with carb cleaner/acetone or some other solvent, plugging both ends, and let it soak.

any opinions?

[hanleyclifford]

Idea 3 - remove idle adjusting screw regularly and blast hole with starting fluid or carb cleaner.

Idea 4 - the conventional wisdom among professional captains is that engines should be run every day or every other day at the least.

[JOHN COOKSON]

I don't like the idea of sucking anything flammable or explosive into a vacume cleaner.
Maybe a "cheese free diet" that is change additives would work.

TRUE GRIT

[Mo]

I make is a practice to remove the carb during winterization every fall, take the carb apart and clean it. It goes back on the day of start-up in the spring and only an adjustment or two and good for a season. Now, I might get away without doing that, who knows, but since I started that practice no issues.

Common issues when ethanol comes into the picture:
-years of build-up in tanks from years of using Non ethanol gas, subsequent wildlife growth as gas left in tanks etc...becomes fuel-borne and heads downstream to filters, carb resulting in fuel delivery issues.
-rubber line incapability
-water accumulation as a result of using ethanol because it draws moisture from the air.

[HalcyonS]

Common issues when ethanol comes into the picture:
-years of build-up in tanks from years of using Non ethanol gas, subsequent wildlife growth as gas left in tanks etc...becomes fuel-borne and heads downstream to filters, carb resulting in fuel delivery issues.
-rubber line incapability
-water accumulation as a result of using ethanol because it draws moisture from the air.[/QUOTE]

re the third - what kind of fuel lines are susceptible?
re the forth - this water absorbance means water separation filters are pointless now?
As an aside, I recall the idea from long ago of water injection as a way of increasing expansion and efficiency - water turns to steam upon spark ignition - it always seemed like an interesting idea - are we getting it for free now?

[HalcyonS]

Idea 4 - the conventional wisdom among professional captains is that engines should be run every day or every other day at the least.[/QUOTE]

that's all very well for professional captains, but not possible if you're not a live-aboard or your boat is an hour away and you have a job, etc. My engine runs every week or every other week, its the best I can do. I'd like an engine that understands this.

[HalcyonS]

[QUOTE=hanleyclifford;78308]Idea 3 - remove idle adjusting screw regularly and blast hole with starting fluid or carb cleaner.

good plan!

[hanleyclifford]

Idea 4 - the conventional wisdom among professional captains is that engines should be run every day or every other day at the least.

that's all very well for professional captains, but not possible if you're not a live-aboard or your boat is an hour away and you have a job, etc. My engine runs every week or every other week, its the best I can do. I'd like an engine that understands this.[/QUOTE] It's all part of the progression. First you get the boat. Then you move the boat up to the house when not in the water, or move yourself down to the boat. Then you start asking yourself, "...do I really need the house?..." (somewhere along the line wife input occurs)..

[JOHN COOKSON]

re the third - what kind of fuel lines are susceptible?
re the forth - this water absorbance means water separation filters are pointless now?
As an aside, I recall the idea from long ago of water injection as a way of increasing expansion and efficiency - water turns to steam upon spark ignition - it always seemed like an interesting idea - are we getting it for free now?

R\E third: Any fuel lines that are not ethanol rated are suseptible and suspect.
R\E fourth: The ethanol adsorbs water, phase separates and sinks to the bottom of the tank where it is aspirated by the tank pickup tube. Hopefully the filter(s) will keep the water out of the rest of the fuel system and engine.

TRUE GRIT

[romantic comedy]

My understanding was that water injection was used to help stop detonation and preignition and knock.

[HalcyonS]

[QUOTE=hanleyclifford;78325]My engine runs every week or every other week, its the best I can do. I'd like an engine that understands this.

So, seriously, what can we do to ensure reliable start/run with irregular use? surely always has been the case for most A4s. What are the main problems -

1. moisture in head? - build a device that fogs the engine with MMO at shutdown?

2. gunk buildup in carb? Differences of opinion about draining fuel lines

3. flat battery...

[ndutton]

Simon, has your engine been hard to start since the cheese was cleaned up? Has the cheese returned?

By itself ethanol isn't the devil's brew it's made out to be. Sure, it's popular to blame it for everything but the truth is if all your fuel storage and delivery systems are in good order it shouldn't make any difference. As for degradation due to absorbed moisture, our two boats are in the same climate, both have their fuel tanks vented to outside air, both have prolonged layoff periods yet mine doesn't suffer from carburetor cheese and starts within seconds regardless of layoff time. I use no commercial additive, only 1% MMO per Don's recommendation (makes it a little smokey but not bad), rebuild my carburetor annually as a regular maintenance item, polish my fuel annually right before a filter change, don't buy fuel at the dock but rather schlep it to the boat in jerry cans filled at a local high volume gas station, have all A1-15 alcohol rated fuel lines and aluminum fuel tanks. I haven't run my engine in weeks but I know it will start within seconds next time I try, always has. Contrary to common advice on this forum, I have so much confidence in easy starting I always have my thru-hull open before I start.

I wouldn't give up the search just yet for the source of the cheese simply by writing it off to ethanol.

[joe_db]

How I keep my engine easy to start:
1. I carry gas down from the car gas station. I don't buy the marina gas. They will be selling the gas they bought in October until at least May or early June.
2. I shut the fuel pump off and run the gas out of the carb when I am done for the day.
3. I fixed the O-ring on my fuel fill to keep water from getting into the tank.

BTW- I found out the hard way that the Racor cannot deal with the goopy mess made by phase-seperated ethanol-water-gas mixtures.

[Dave Neptune]

Additives and tanks

I'm with Neil here as I have not ever had a problem with the E-fuels. My engine has run once since October's last cruise and that was to charge the batteries back up as I do not use shore power on them unless their dead.

Before ethynol was in the fuel I would add some "alcohol" to the fuel to absorb any water in the tank. The fact that the E-fuels suck up water is not particularly bad unless it is to much water and sits so long it can PHASE SEPARATE and that is heavier than the fuel. It sits on the bottom and when there is enough to get to the pick up tube trouble has arrived.

I have a fuel separator filter and it is now at least 7 years old and never been changed. I did change the polishing filter when I up-graded my fuel lines a regular maintenance project every 5~6 years.

I run the engine a lot during the season and it sits for about 4 months inactive and it has been done as such for 29 years under my ownership.

I think the biggest reason I have no real fuel issues is that I do not use any additives in the fuel and won't! I honestly feel that the mixing of additives is very bad and the accumulation of the crap in some tanks is from all of the additives mixing with something and sticking around and sticking around and sticking around~~~eventually raises lil ole "havoc" and he is no fun!

Dave Neptune

[joe_db]

One clue I got:
EVERY gasoline powered boat on my dock had the fuel polishers and mechanics fixing things at some point one year.
OTOH there was no epidemic of dead cars on the island.
So I started buying gas for the boat where I got my car gas