PDA

View Full Version : What is this s#*t in my fuel?


capetrees
05-08-2009, 10:37 PM
For the past two years I have owned a Scag 36" walk behind with a 15hp Kawasaki. I have had to take the machine to the shop 3 times for clogged carburator issues. The same thing comes back as the cause, some kind of vasaline like gel in the bowl that gets sucked into the carb and clogs it. I've been told its from old gas but the fuel in my tanks this last time was less than one week old. What is this crap and is there something I can add to the fuel that will get rid of this stuff or prevent it from happening? FYI, the gas we have around here has up to 10% alchohol mixed into the gas. Could this be doing it?:confused:

Also, I don't know if its related but my engine revs up and down while its idling, not a consistant rpm. Is this related? What causes it and how do I fix it?

ed2hess
05-08-2009, 10:44 PM
We are all going to have to look at converting to propane. It is a clean
fuel and just a few things to work out in my mind. One is the need to get delivery of those tanks and another is rebate for cost of installation.

milike
05-09-2009, 09:41 AM
For the past two years I have owned a Scag 36" walk behind with a 15hp Kawasaki. I have had to take the machine to the shop 3 times for clogged carburator issues. The same thing comes back as the cause, some kind of vasaline like gel in the bowl that gets sucked into the carb and clogs it. I've been told its from old gas but the fuel in my tanks this last time was less than one week old. What is this crap and is there something I can add to the fuel that will get rid of this stuff or prevent it from happening? FYI, the gas we have around here has up to 10% alchohol mixed into the gas. Could this be doing it?:confused:

Also, I don't know if its related but my engine revs up and down while its idling, not a consistant rpm. Is this related? What causes it and how do I fix it?

you don't put vaseline in your tank do you?:hammerhead:

evedn though it's petroleum based, it is not rated for IC engines.;)

tenndigger
05-09-2009, 10:21 AM
The only thing I can think of is possibly the 10% ethanol gas is eating away the inside of your gas tank. Is it plastic or metal. If metal it could be eating away the coating inside.
I would replace the fuel line and put an inline gas filter between the tank and carb . I try to not use ethanol blended fuels in any small engines. Suppposedly the ethanol will deteriorate older rubber lines and some plastics. I have begun to use SeaFoam additive to fuel in all small engines tanks. A gallon of SeaFoam is $50 at the parts store. Many small engine mechanics recommend it.

ricky86
05-09-2009, 12:34 PM
It could be a glycol substance and it shows up with old fuel. It is a chemical reaction that happens with fuel as it ages. Yes, Sea Foam is an additive that people use. Additives are the problem to begin with. Why add more?

capetrees
05-09-2009, 01:34 PM
Tenndigger,
There already is an inline fuel filter on the machine and the tank is a factory plastic tank. I can't imagine the tank being degraded by gasoline. Millions of gas tanks are made of plastic.

I have heard of this Seafoam for marine engines. Someone actually showed it to me yesterday for the first time. My guess from reading the label is that it is a petroleum/alchohol additive used to "cure all your problems". As mentioned, why add additives to something that has an additive, the 10% alchohol? I think the gel that is showing up is possibly a small amout of water mixing with the alchohol but I can't think of how that is happening on the chemical level. Alchohol is supposed to disolve water or at least dissipate it so it burns along with the gas, thus Drygas.

Hmmmm......

ricky86
05-09-2009, 02:07 PM
My post isn't a theory, feeling, guess, conjecture or perceived experience. It is from tests run by an small engine manufacturer. And none recommend a fuel additive. Alcohol doesn't dissolve water, it absorbs it, that's part of the chemical reaction part

Breezmister
05-09-2009, 05:07 PM
What is this crap and is there something I can add to the fuel that will get rid of this stuff or prevent it from happening? Federal underground fuel storage tank regulations?

What I would suggest is get a better fuel filter. Ask your dealer for a lower micron filter or go on line and check out the different fuel filters.

As for the stuff in the fuel, I had a problem a few years back where I got gas from the bottom of a in ground tank, from all the crap that is in fuel. As the gas starts to break down, will settle to the bottom of the tank and if the tank is near empty, you are going to get that crap in your fuel. Fine out when the tank was filled, if its more then a week, go some place else, or go to a gas station that has a lot of use. When new fuel is added to a in ground tank, all the stuff is mixed back into the fuel.........

topsites
05-10-2009, 01:05 AM
Get your fuel from another gas station, see if that fixes it.

wallzwallz
05-10-2009, 08:54 AM
I'm in MA also and since they added the alcohol have had similiar problems in equipment. My old Gravelys have the most problems, I think the alcohol pushes all the crap through and don't know why it gels.

treemonkey
05-10-2009, 10:06 PM
You might want to study up on the phenomenon known as phase separation in ethanol fuel. From what I have studied, E-10 fuel is not as bad as everyone makes it out to be. But, one has to be aware of it's characteristics regarding use, storage, and it's affinity to water AND change a few basic use/storage practices.

I have not had phase separation happen and don't know if the gel you see is the result of it.

When my workplace changed over to E-10, I spoke with a helpful filter guy at Champion Labs/Petroclear to learn how to manage my storage tanks.

Here's some frightening things he told me: "Once the Ethanol absorbs more than the recommended amount of Water, it becomes heavier than the fuel and drops out of suspension, which is Phase separation. AND....

E-10 can hold a maximum of 0.5% water up to 60 degrees F. Above that, it will phase separate. In ground storage at 54 degrees could hold the 0.5%, but when it warms up in vehicle, could phase separate there."

Are you getting bad fuel? Do you store it improperly? the boat industry had to rethink their practices to overcome E-10 problems.

Here's an informative site, but this company sells E-10 test kits and their site is very biased...millions of vehicles are running on E-10 without problems. http://www.fueltestkit.com/about_ethanol_fuel.html

Stabil says there is no additive to prevent phase separation. Pri-G says it "lessens" it up to a certain degree.

GravelyNut
05-10-2009, 10:19 PM
The gel you are finding may be your fuel line in the tank breaking down. Some makers of ZTRs have had to change their in tank hoses due to them breaking down.
Gravely owners with black grommets at their tank need to have theirs checked. Current ones have orange grommets.

capetrees
05-11-2009, 10:34 PM
Thanks treemonkey.
That seems to be whats happening around here with the gas. Others have reported the same issues happening, especially down at the repair shop where homeowners are showing up with clogged fuel filters and carbs because they buy 5 gallons of gas for their mowers and use them once a week. The gas stays around for months and goes bad and the gell is showing up elsewhere. I guess the trick is to run super fresh fuel all the time and if storing, run it dry. The old idea of filling the tank to deter moisture in the tank doesn't hold true anymore. The gas will just go bad anyway.

freddyc
05-12-2009, 02:54 PM
Tenndigger,
There already is an inline fuel filter on the machine and the tank is a factory plastic tank. I can't imagine the tank being degraded by gasoline. Millions of gas tanks are made of plastic.

I have heard of this Seafoam for marine engines. Someone actually showed it to me yesterday for the first time. My guess from reading the label is that it is a petroleum/alchohol additive used to "cure all your problems". As mentioned, why add additives to something that has an additive, the 10% alchohol? I think the gel that is showing up is possibly a small amout of water mixing with the alchohol but I can't think of how that is happening on the chemical level. Alchohol is supposed to disolve water or at least dissipate it so it burns along with the gas, thus Drygas.

Hmmmm......


I've tried seafoam previously with zero results---waste of money to me. Din't do anything but cost me money.


I had a similar issue with a 17 hp kawi engine--plastic tank and so on.

I took the tank off, totally cleaned it till it was bare, replaced the fuel filter, took apart the carb and totally cleaned it and flushed brand new high octane thru the whole deal. Runs like a million bucks now, but when I piece-mealed it by working on one compoent at a time it kept coming back.

lawnjocky
06-01-2009, 07:43 PM
Just a thought, don't know if this is to blame. Has your fuel dealer had any work done to their tanks, lines, etc.. Several years ago I had a truck break down with fuel problems. Dropped the tank and pulled the pump. The screen/sock had what looked like snot on it.The truck had a locking cap on it so I knew no one had spiked my fuel. We drained the tank, changed the pump and filters. Week later we were back dropping the tank again. Steamed that sucker this time around and changed gas stations. That cured the problem. So what caused the snot? Found out later it was probably some kind of silicone that had not cured properly. The silicone was from the gas station that had work done to their tanks.

topsites
06-02-2009, 01:11 AM
Gas has always gone bad over time if left sitting, ethanol might have made it
worse but the problem isn't new.

Always run it out of fuel before storing it, and don't keep fuel sitting for more than 60-90 days.