# Yamaha 40hp 2-stroke and Ethanal...facts/fiction?



## YamahaC40Guy (Apr 27, 2010)

He guys, haven't posted here in a while but have been lurking. Have a question for you all, hoping you can help; 

After running my '99 C40 for a couple of seasons, I've had my first problem with it. Here is the story;

1.run between April and October, 4-6 days a month on average
2.winterized prior to storage in outdoor/covered spot (in southern Ontario, Canada)
3.run Yamalube as the oil, use low 87 grade gas
4.trouble-free service, decent fuel-economy

This spring, it fired-up fine, burned-off the rich gas in the lines he put in there (with stabilizer, as I understand it) Everything seemed normal, but it did seem to smoke a bit and really burn through the gas. Then, didn't idle well. Next-up, didn't reach full power when opened-up and would stall when in neutral. I did everything I could do to remedy this (changed the plugs :wink: ) and while the old ones were gummed-up pretty good, it did nothing to remedy the situation. Off to the mechanic.  

After a total tear-down/clean-up of the carburetor he told me that it was a build-up of ethanol residue that had clogged things-up. I asked if a fuel stabilizer would have prevented it, he said that a product like Sea Foam or Yamaha's "Ring Free" might, the latter being something plenty of Yamaha owners swear by. Asking around to fellow boaters I know, they told me that it isn't the ethanol in the gas, rather, the ethanol's effect on plastic gas tanks and rubber fuel hoses that causes this residue. (?) I've now read enough about Ring Free to order a bottle, but is there something I should be doing differently? I haven't run the boat since the work was done, but I'm about 100% sure it'll now be running like a top now. Just hoping to avoid this problem if possible. I've read that running high octane (little/no ethanol added) isn't a good idea for outboards.

Thanks for taking a moment to respond,
Rob


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## Quackrstackr (Apr 27, 2010)

Ethanol does not leave any residue as it is actually an alcohol.

Most stabilizers keep that alcohol from absorbing excess moisture but they don't really have much of an effect on the alcohol breaking down the plastics and rubber in your fuel system. It's simply a bad side effect of ethanol gasoline and there's no ethanol remover that I am aware of. Some of the stabilizers will help clean the fuel system but you really still have the material breakdown problem.

The only true way to solve it is to buy ethanol free gas or hope to eventually replace all of the affected components with ones that are ethanol resistant.

Ethanol gas is bad news on older fiberglass fuel tanks.


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## bassboy1 (Apr 27, 2010)

Ethanol has two major problems. First, it will eat the guts out of the whole fuel system on older boats (up until recently, boat designers had no clue of the need to make ethanol impervious fuel systems), allowing residue of these innards to clog stuff up, like Quack mentioned. Secondly, it has this inane ability to suck all sorts of water into the fuel system, as ethanol naturally attracts and absorbs water molecules in the air. Both of these make it bad news for fuel systems. 

Ah, the joys of reducing emissions. Thank you EPA :roll: .


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## Loggerhead Mike (Apr 27, 2010)

> I've read that running high octane (little/no ethanol added)



im not sure about canada but in my parts high grade still has the same amount of ethanol and you really never know how much eth your actually get in the fuel. i test fuels all the time with 15-20 percent eth (10 is legal limit). You may of got a bad batch causing your rig to run way lean (the no smoke issue) along with deteriorating your fuel system

drain the gas out of your carbs and fuel line when you let it sit.


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## Quackrstackr (Apr 27, 2010)

Loggerhead Mike said:


> > I've read that running high octane (little/no ethanol added)
> 
> 
> 
> im not sure about canada but in my parts high grade still has the same amount of ethanol



same here.

octane rating in these parts has nothing to do with ethanol content.


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## njj502 (Apr 27, 2010)

All of my lawn equipment (not the ridin' mower) is 2 stroke. I've found myself cleaning carbs more often. I guess it's the crap fuel now days. My Lawnboy bought in 97 has over 1000 hrs on it has never had the carb off it and needs it now. 

Thanks CARB & EPA for giving us crappy gas and now Diesel fuel that causes nothing but issues.


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## Quackrstackr (Apr 28, 2010)

If your gas phase separates, you need to dump it.. not run it through your engine.

Phase separation is when the water absorbed by the ethanol reaches peak saturation which causes the alcohol and water to separate out of the fuel. This water and alcohol layer will be on the bottom of your tank.. right where your fuel line is pulling from. Filter or not, I'm not going to chance running pure water and alchohol into my motor.


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## Quackrstackr (Apr 28, 2010)

That is all well and good but if you have no phase separation, you have no octane drop, either.

BTW... all of these additives for ethanol advertise themselves to be the best of the crop.

If the OP is having issues from residue caused by ethanol reacting with his fuel system (read dissolving certain parts of it), there isn't an additive out there that will fix the problem.


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## YamahaC40Guy (Apr 28, 2010)

Thanks for the input guys, much appreciated. There remains some debate about all of this, I'm reading this with great interest. I did order a bottle of the Yamaha "Ring Free" as I read some glowing reports about it. I will run some slightly higher octane fuel through it next time out, see if I notice any difference. 

Do any of you use, or know anyone that uses Ring Free? Mentioned in the third last paragraph. https://www.yamaha-motor.com/outboard/events/dynamicevent/3/1014/the_boaters_log_-_vol_1_no_7.aspx

A description of what it does; https://www.simyamaha.com/Yamaha_Yamalube_Ring_Free_Fuel_Additive_p/acc-rngfr-32-00case.htm

Rob


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## Loggerhead Mike (Apr 28, 2010)

sounds like any other carbon cleaner to me. go read sea-foams websight i think the same person wrote them :LOL2:

there is no product that will rid the alcohol from the fuels. they only emphasize on how it will help keep water out, clean carbon ect ect. water isnt deteriorating the fuel system nor is it a problem unless you are running bad gas




> Lastly, *and maybe most importantly*, use your boat a lot. If you make certain the gas doesn’t have the opportunity to get old, you greatly decrease your risk of fuel-related issues



the only cure. eth. will only rot stuff away when its sitting


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