What is this gel-like substance in my carb? Mercruiser 3.0L Alpha 1

[vtx531]

Middle of last summer, I had part-throttle fuel issues. Later it turn into issues idling too. I was able to adjust the idle mixture enough to get it to run but not very good.

I put it away for winter, fast forward to this week...it started okay and then later it would die and not even idle.

Pulled the carb and here are the pics...

Is this from E10 fuel?? I understand that E10 can cause water in the fuel (not my issue) and corrosion (not my issue), and octane/knocking/missing (not my issue). But this??

I normally use regular unleaded pump gas. All of it is E10 in Michigan. I never used rec gas in the 10 years I have owned the boat because A. it is expensive B. not nearby C. I never thought the ethanol was a real problem

I should also say that there is a very fine screen/strainer on the fuel line before the fuel enters the carb and the screen/strainer was perfectly clear so I don’t think the issue is originating in my fuel tank or anywhere else upstream.

So what is this and how do I avoid it?

 

[vtx531]

Also, it is a 2006 model year - so the fuel system should be safe for E10 I think.

 

[Bondo]

I should also say that there is a very fine screen/strainer on the fuel line before the fuel enters the carb and the screen/strainer was perfectly clear so I don’t think the issue is originating in my fuel tank or anywhere else upstream.

Ayuh,..... Welcome Aboard,...... I don't run ethanol, so can't say, but, there should also be a fuel filter inside the fuel pump,.....
'n if you don't have one, you should add a canister type fuel filter just ahead of the fuel pump,....

 

[tank1949]

Good luck totally eliminating all contaminates from carburetors. I have experiences some success by draining fuel/water separator every couple of weeks during boating season and keeping tanks full. Yet, condensation seems to always win and end up inside carbs.. I run the cheapest gas that I can find. I tried the non-alcohol more expensive gas years ago but had the same results.

 

[Earl Cordova]

We have no choice but to use gas with ethanol.
So I put Sta-Bil 360 Marine in every fill up.
It is advertised as an ethanol treatment and stabilizer.
Even if it doesn't work, it makes me feel better.

 

[tank1949]

We have no choice but to use gas with ethanol.
So I put Sta-Bil 360 Marine in every fill up.
It is advertised as an ethanol treatment and stabilizer.
Even if it doesn't work, it makes me feel better.

It is also my understanding that some of the older fuel hoses do not play well with alcohol crap. 2006???? May have better rubber????

 

[nola mike]

It is also my understanding that some of the older fuel hoses do not play well with alcohol crap. 2006???? May have better rubber????

No, e10 has been fine for decades. My '86 says it's fine to use. Old gas will turn into varnish and gel up. Doesn't sound like you had it in there long enough, but that looks like the result.

 

[dingbat]

Looks like the liner out of a fuel hose.

When was the last time the fuel hoses where changed?

A 15 yro fuel line is well past it’s life expectancy of 10 years, at best

 

[vtx531]

Good luck totally eliminating all contaminates from carburetors. I have experiences some success by draining fuel/water separator every couple of weeks during boating season and keeping tanks full. Yet, condensation seems to always win and end up inside carbs.. I run the cheapest gas that I can find. I tried the non-alcohol more expensive gas years ago but had the same results.

The cleaning seems to be successful. Last time I had problem I soaked it in one of the gallon paint can style carb cleaners. This time I just removed all the jets and sprayed with carb cleaner and compressed air blowout. I always keep the tank filled up after each outing. No fuel water separator on my boat. I am glad you shared your experience with trying the expensive gas and I think I would have the same results too.

We have no choice but to use gas with ethanol.
So I put Sta-Bil 360 Marine in every fill up.
It is advertised as an ethanol treatment and stabilizer.
Even if it doesn't work, it makes me feel better.

I was looking at Stabil 360 Marine but out of all their advertising, none indicates it would solve this problem. It talks about preventing rust and corrosion (no issues) and “Clear and prevent harmful gum, varnish and buildup throughout the combustion chamber and injectors.”...funny it doesn’t mention carburetors!!! Hmmm wonder why? Pump gasoline already has additives in it to do the things that Stabil claims to do.

It is also my understanding that some of the older fuel hoses do not play well with alcohol crap. 2006???? May have better rubber????

Think I read 2003 is the start of E10 safe?

No, e10 has been fine for decades. My '86 says it's fine to use. Old gas will turn into varnish and gel up. Doesn't sound like you had it in there long enough, but that looks like the result.

Old gas, whether E10 or not? Sounds like it.

Looks like the liner out of a fuel hose.

When was the last time the fuel hoses where changed?

A 15 yro fuel line is well past it’s life expectancy of 10 years, at best

I had no idea about replacing fuel hoses every 10 years. I will look into it. I think the fact that the screen was clear entering the carb would point to elimination of the fuel lines as a possible cause?



At this point, I think I’ll keep running the E10 and add a couple steps onto my winterization routine -

1. pull off the top of the carb
2. suck all fuel out of the bowl
3. spray jets with cleaner
4. blow out with compressed air

Basically will have a gauranteed fresh/clean carb to start out each season and a way to monitor what is happening in there on a regular basis.

 

[tank1949]

The cleaning seems to be successful. Last time I had problem I soaked it in one of the gallon paint can style carb cleaners. This time I just removed all the jets and sprayed with carb cleaner and compressed air blowout. I always keep the tank filled up after each outing. No fuel water separator on my boat. I am glad you shared your experience with trying the expensive gas and I think I would have the same results too.

I was looking at Stabil 360 Marine but out of all their advertising, none indicates it would solve this problem. It talks about preventing rust and corrosion (no issues) and “Clear and prevent harmful gum, varnish and buildup throughout the combustion chamber and injectors.”...funny it doesn’t mention carburetors!!! Hmmm wonder why? Pump gasoline already has additives in it to do the things that Stabil claims to do.

Think I read 2003 is the start of E10 safe?

Old gas, whether E10 or not? Sounds like it.

I had no idea about replacing fuel hoses every 10 years. I will look into it. I think the fact that the screen was clear entering the carb would point to elimination of the fuel lines as a possible cause?



At this point, I think I’ll keep running the E10 and add a couple steps onto my winterization routine -

1. pull off the top of the carb
2. suck all fuel out of the bowl
3. spray jets with cleaner
4. blow out with compressed air

Basically will have a gauranteed fresh/clean carb to start out each season and a way to monitor what is happening in there on a regular basis.

I had a 1995 Proline that had sit for some time and rubber fuel lines had left black crap. I always suspected alcohol was the culprit, but it may have been age.....

 

[Mcfltfyter]

It looks like someone added marvel mystery oil to the fuel at some point. When it sits in the float bowl, the gas and oil evaporate but the mystery stays behind for the owner to marvel.

TLDR; I don't know what that gel is.