Ethanol gas Mix

[Sebrof]

I have a 1991 Johnson 4cyl 2stroke 115hp...i read a BOAT/US article about the horrors the new ethanol gas mix is causing in old 2 strokes( gumming carbs, gel'ing in the filter and lines). This season I've had alot of trouble with rough idle and stalling at high rpm or coming back up to speed after a prolonged wot run. This article seems to point me in the crapped up carb mindset..(truth be told I was heading there anyway). What have you guys heard about this fuel? thanks...Seb

 

[Silvertip]

Re: Ethanol gas Mix

Truth and untruth depending on the articles and stories. Ethanol is an excellent fuel system cleaning agent. As such older engines that already have gunk and crud in the fuel systems will likely have issues when switching to ethanol blended fuel. Once cleaned, the engine will live normally. We in the midwest have been using this stuff for years so we've dealt with it in older cars, trucks, tractors and about anything with an engine. Run a few tanks and if the engine begins to act up, do the carbs, replace filters, check fuel lines and fittings and go again. You may need to replace a couple filters until the tank is cleaned. You may even need to pull the pickup to clean the screen. Just don't continue to run the engine with it acting up as its telling you its lean. 2-strokes don't like lean.

 

[rickdb1boat]

Re: Ethanol gas Mix

Well, what I have heard is that if your system(Tank, Lines, Filters, Carbs, Etc) is clean and your carb kits are up to date, there should be no problems. Most carbs from around 1990 on up should be Ok. This is just what I've heard from a mechanic where I shop. There are alot of opinions here that have been discussed in the not to distant past....

 

[Silvertip]

Re: Ethanol gas Mix

That's very true. My nine-year old Evinrude ran on ethanol blended fuel its entire life. Last year I rebuilt the carbs just because it was due, and I found them absolutely spotless. It ran off a plastic portable tank that was not affected by ethanol but it was affected by the plastic debris in the tank from the drilling operations. Most engines by 1990 or so had fuel system components that could tolerate ethanol blended fuel. Some earlier models did have problems with deterioration.

 

[hunt-fish.com]

Re: Ethanol gas Mix

I too think that the blended gas we have in DFW is the cause of my rough idle, stalling etc... I guess it's possible that the ethanol turned loose some of the gum in the system somewhere and caused poor performance clogging something. I hear an additive advertised on Ed Wallace's radio program about cars called "RXP". It's suppose to make the ehtanol burn more completely and help with issues caused by ethanol. Anyone tried it in an outboard with 50:1 mix?

Thanks,
John

 

[WillyBWright]

Re: Ethanol gas Mix

Keep in mind that oil mixes well with gasoline and poorly with alcohol. If there happens to be any moisture in the gas, it can really get bad. Considering where you operate a boat, it's about certain. Avoid ethanol if you can. If you must, make certain there is no water in your fuel tank(s). If you have a built-in tank, a water separating fuel filter would be highly advised.

 

[Sebrof]

Re: Ethanol gas Mix

I have a 1991 Johnson 4cyl 2stroke 115hp...i read a BOAT/US article about the horrors the new ethanol gas mix is causing in old 2 strokes( gumming carbs, gel'ing in the filter and lines). This season I've had alot of trouble with rough idle and stalling at high rpm or coming back up to speed after a prolonged wot run. This article seems to point me in the crapped up carb mindset..(truth be told I was heading there anyway). What have you guys heard about this fuel? thanks...Seb

 

[Sebrof]

Re: Ethanol gas Mix

As usual, you guys come thru...Thanks. That article I read was nothing but doom and gloom. As I said I was thinking of doing the carbs anyway just because it's time and I had ordered the gaskets and o ring kit acouple of days before the engine acted up. I hoping that once I burn off the old gas mix of the MTBE style gas from last year and the ethanol from fill ups this year and start running straight E10 that the fuel system should settle down...keep you posted..thanks again, Seb

 

[limacina]

Re: Ethanol gas Mix

Ev/Johnsons just spit and cough at idle, their happy at high speed. Consider it a nuance.
I think everyone is pariniod this summer, including myself. Anytime I hear something different, I say "Ethanol!"
I run twin '97 115 Johnsons, They have spit and coughed since I can remember, I only have 500 hours on them.
I've had one carb apart once due to a gas leak. They're sealed with very small dia. orings that wear out. Often, the orings are either leaking gas out or sucking air in. I am not looking fwd to rebuilding 8 carbs, but I'm getting to that stage.
I'm guessing ethanol doesn't cause any problems with 99% of us, but mabey it enhances existing problems??

 

[Silvertip]

Re: Ethanol gas Mix

Ethanol is actually 105 octane so it burns very well. I have a new Impala that runs on E-85 which is the opposite of the regular blended fuel you buy at the pump (85% - 90% regular gas and 10% - 15% ethanol). In the midwest (and expanding elsewhere) E-85 is now available which is 85% Ethanol and 15% regular gas. The car performs much better on Ethanol but fuel mileage is substantially less than with regular blended fuel. Poor running cannot be blamed on ethanol. Cleaning up gum and varnish deposits, and in very old engines, fuel component degradation can be.