View Full Version : How much ethanol is bad?


Rstark
May 10th, 2022, 09:19 AM
Hi all, I was thumbing through my owner’s manual(OM) (1st time I read it 😂). Earlier, I’m not sure where but I read something that said you should use 91 octane. That’s when I dug up the OM. It confirmed 87 octane was the way to go. I run only 89 octane non-ethanol. I could switch to 91 octane, but I seriously don’t think I will get any gains or pluses in doing so. I don’t want anything but gas, minus the ethanol.

So my question is how much ethanol fuel do you go through before you see any signs? (On average) A couple that come to mind are rubber fuel hoses and injector clogging. I’ve only found two non ethanol gas stations and one more station several miles away. Sometimes you are simply not in the area of non-ethanol gas stations and need gas. So how bad or good is ethanol?

thedrewski86
May 10th, 2022, 09:37 AM
I've seen manuals specify 91 RON fuels which are close to the US 87 octane rating. RON is just a European rating. Ethanol really sucks if you have carburetors; it has very noticeable effects after a bike sits for just 3 weeks. You probably won't notice it as much with your fuel-injected 300. I run Sta-bil in both my bikes now as I don't get many miles on them. My carb'd 250 really needs it as the ethanol fuels degrade so much faster.

DannoXYZ
May 10th, 2022, 02:57 PM
Yeah, any amount of ethanol is bad for carb bikes. Due to vented tank and carbs, moisture sneaks in from outside and causes separation of ethanol from gasoline.

On EFI bikes, not that big a deal since systems is fully sealed.

jkv45
May 11th, 2022, 06:53 AM
Use whatever is the lowest octane gas you can get without ethanol.

No need for anything more than 87 for the Ninja, unless you have to go higher to get away from ethanol. Excessive octane reduces power.

Gas without ethanol will make a carbed engine run richer than gas with ethanol - which usually means better.

I don't run gas with ethanol in anything with a steel tank, or any small 2-stroke.

Gas with ethanol goes bad quicker than gas without.

If tuned precisely for it, gas with ethanol can produce slightly more power, but it's not significant in most applications and doesn't offset the disadvantages, IMO.

Alex
May 11th, 2022, 08:49 AM
Ethanol free gas is not available to huge portions of the population. Any large metro area isn't going to have it nearby. It's only available where many people *aren't*. This site catalogs stations that sell ethanol free gas by state: https://www.pure-gas.org/

jkv45
May 12th, 2022, 06:52 AM
Sta-Bil makes a couple additives to treat ethanol gas if that's all you can get.

I believe it's Sta-Bil 360 and Sta-Bil Marine.