ethanol carb corrosion?

[pcrussell50]

the motor on my fishboat is a carbureted 90hp merc FourStroke. these motors are notorious for tiny passages that clog and gum/varnish up easily.

BUT

I use a strong additive package in every tank, (StaBil AND a fuel system cleaner, sometimes techron, sometimes quickleen). Every tank.

so, when i got misfiring and poor running earlier this year, i scratched my head and pulled the carbs for a good ultrasonic cleaning. they were amazingly clean of gum and varnish--spotless really. (i guess my additives work).

but one of the carbs had a badly sticking float needle that was fouled with a very hard, dry white deposit that did not come clean in the heated ultrasonic cleaner (i use kerosene in it). after searching around on the whaler forums, one smart guy who does not post much, mentioned corrosion from water that separated out of ethanol tainted fuel. he thinks the carb bowls are coated with something and if the coating wears off even a little, water can start the now bare aluminum to oxidizing. and once that happens, it will keep coming back fairly quickly. the solution seems to be to replace the carb body itself with a new one that does not have the compromised coating.

anyhow, marine techs on here, does that sound believeable to you guys? is this something you guys deal with on modern carb motors? what would you do about it?

-peter

[Mr. Demeanor]

You carbs are clean from the E10, not the additives. I run no additives and ever since E10, my carbs stay spotless. You have to think about the fact that your pouring straight alcohol (a very strong solvent) at a ratio of 1 gallon for to every 9 gallons into your tank. Between that and the other additives added by the fuel companies, there really is no need to add anything else. The bad side of E10, nothing you can pour in your tank will stop it from eating your fuel lines, swelling seals/o-rings, etc.
But I am sure someone will disagree...

[Forkin' Crazy]

I haven't had any problems on my boat motor, but I have on my dirt bike. I let it sit for two weeks with out running it once. It had green corrosion on the brass parts.

[WATERWINGS]

But I am sure someone will disagree...


WHO...?......someone with a twin turbo car motor boat?

[WATERWINGS]

We can still get 100% real 93 octane gas here at one station here in town.....not sure what it costs now, cause I have been boatless all summer.....it got as high as $4.29 at one time......I think its around $4 now......BUT....I would think since it doesn't contain ethanol, it shouldn't go up when the ethanol fuel goes up..........(who am I kidding) ?

[jenksam]

Here is the deal

i see this every day, if you have a metal carb (just about all but omc :) ) if you do not run it much and let it sit for any period of time (weeks to months) you will get a build up. It will look white to yellow in color and will at times tarnish your brass parts. The e10 will carry water with it. By this i mean i have seen with my own eyes go right through a water separator filter. Had a customer that kept getting water in the engine, so we put a water sep filter on it still had a problem and no water in the sep fliter, pumped the tank with a new water sep on it. Sat right there and watched it the ethanol brought the water straight through. Didnt catch a drop in the filter.
As far as my four wheeler the efi bike dont seem to mind it much but for some reason the carb bike i dont even think about it any more. It gets the old race fuel:)

the bad thing is i have to tell the customers this just about every day. Most of them get it after seeing the parts or pictures. The congress knows that there are problems and still do nothing about it.
I am not sure and i hope that there is a chemist on here. But the deposits that i have seen look like corn starch. That being said, i know that shell is starting to use sugar cane ethanol may be that will be better. They have been using this in brazil for many years. Its 7x more efficient to produce than corn.

[VectorPat]

I have seen several carbs with this pitting and its usually with boats used in salt water, fresh water might do it too but most of my business is salt. Im guessing the ethanol is absorbing it. You can clean them but eventually it will come back and if its too bad usually have to replace the bowls and occasionally the whole carb. I use an ultra sonic cleaner too. Ive never used kerosene, Ive always been a little paranoid about it flashing while being heated in the cleaner. I use some of the cleaners the ultra sonic companies sell and have had pretty good results with them.

[Mr. Demeanor]

Alcolhol is corrosive to metal. I used to run a drag bike on an alc. blend and we ran a top end lube then flushed out the whole system with real gasoline (back in "the day") after a race. Yamaha outboard VST tanks seem particularly prone to it so maybe different types of aluminum will react differently. My Yamaha carbs have been fine and I have had my Opti fuel rails off and they look fine. Your results may vary.....

I wonder if having the parts anodized if your having continued problems would be a solution?

[Ron V]

I've had a lot of carbs apart in the last 20 years running E-10 here and have never really noticed the problem you are describing. Not saying it isn't possible, but I haven't seen it. I'd be more suspicious of the ethanol cleaning something else that was in the fuel system and depositing it in the carburetor more than actual corrosion. I'm not sure what the formulation is for Quickleen, but I would think it would have corrosion inhibitors in it.

One thing I will say is that I have had problems with stabilizer on a couple of occasions (once with OMC 2+4 and once with Stabil) and no longer use it in any of my stuff.

[pcrussell50]

I have seen several carbs with this pitting and its usually with boats used in salt water, fresh water might do it too but most of my business is salt. Im guessing the ethanol is absorbing it. You can clean them but eventually it will come back and if its too bad usually have to replace the bowls and occasionally the whole carb. I use an ultra sonic cleaner too. Ive never used kerosene, Ive always been a little paranoid about it flashing while being heated in the cleaner. I use some of the cleaners the ultra sonic companies sell and have had pretty good results with them.

great post pat, thanks. i'm not overly worried about flashing kerosene, just because it is so much more resistant to flashing than say, gasoline. of course, i could easily be living under a false sense of security =8-0

-peter

[VectorPat]

How well does the kerosene do with polishing the brass parts? I would love to find something that will clean the brass parts like the old OMC Engine Tuner would.

[Dave Strong]

How well does the kerosene do with polishing the brass parts? I would love to find something that will clean the brass parts like the old OMC Engine Tuner would.

Mercury Power Tune is the next best thing.

Dave

[VectorPat]

I think all the engine tuners are the same anymore, atleast they all smell the same and give the same results but they just arent as strong as they used to be. Thanks EPA :(
I have been using Yamahas cleaner but I just put some in a small stainless bowl and put all the jets in there then float the bowl in the ultrasonic while the carbs are in there for about 20-30mins, the heat really speeds up the cleaning process and it works ok but still cant get the brass parts on the carb to look that good. They are clean but just dont have that look to them you get from the old engine tuner. I want to find something that will work in the ultrasonic but I need about 3 gallons of it.

[WATERWINGS]

I think its around $4 now......BUT....I would think since it doesn't contain ethanol, it shouldn't go up when the ethanol fuel goes up..........(who am I kidding) ?


I guess I was wrong....that gas is once again at $4.29 a gallon......If it contains NO ETHANOL, then why did it go up with the other fuels that contain ethanol ?

[baja200merk]

My 2 optimax 150s need the vst cleaned and the fuel pumps were almost locked up after a few months of sitting k-100 or pri-g will free the pumps up.

heres what I deal with when the snowbirds come back after their pontoon sits for 5 months and they are wondering why it wont run... :eek: This carb is from a pristine super low hour newer 50 yamaha

http://i408.photobucket.com/albums/pp163/hondacr8288/IMG_20120207_132751.jpg

[Markus]

I am not sure and i hope that there is a chemist on here. But the deposits that i have seen look like corn starch. That being said, i know that shell is starting to use sugar cane ethanol may be that will be better. They have been using this in brazil for many years. Its 7x more efficient to produce than corn.

Ethanol is ethanol. I doubt it matters whether it was made from corn, sugar, potatoes or crude oil...

[WATERWINGS]

PLUS....I remember when putting "sugar" in the gas tank was bad....

[Dave Strong]

PLUS....I remember when putting "sugar" in the gas tank was bad....

Sugar will clog fuel filters, if you want it to get past the filters it has to be liquid, ie. pop such as cream soda or coke.

Dave

[VELOCITOY]

...ttt...