The ol' non-ethanol gas talk

I got a hobbit with the dr kit, proma, 19mm phbg blah blah blah. So I recently got the bike pretty much tuned and decided to get some non-ethanol gas since everyone says its alright to use. I've looked up a bunch about it and there doesn't seem to be any performance differences between the two, but it is the only thing that has changed within the past day. Now since I put said gas into it I did premix with the only oil I had which was motul 800 estercore (not double ester like what they sell on treats). And ever since I put it in it's damn near impossible to get up to speed it bogs at mid-throttle to WOT. Would switching gas types affect tuning at all? I have no air leaks and everything else has been onced over and is in working order. wtf mate?

Re: The ol' non-ethanol gas talk

I can see it effecting tuning, but I dont know 100% if the below is correct.

Running straight ethanol requires a huge jet compared to regular gas, so I would imagine even a 10% mix of ethanol would require a larger jet than 0% ethanol.

In fact, this would make sense as to why all the stock bikes I have gotten running the past few years would always need an upjet- even if everything was stock they would all run lean. hmmm.

Who knows though, I am not an expert.

Re: The ol' non-ethanol gas talk

Interesting. I'm leaning towards coincidence but you've got to reply back with what happens when you drain the tank and refuel.

Fuel is one of those highly contentious issues. I had a 250 I swear ran better on Sunoco 94 ultra and worse on Petrocan but everything I know says it's just confirmation bias. No dyno of course but the bike always felt "snappier" on the ultra premium fuel. Octane, ethanol and water content just shouldn't vary enough to make that much of a difference. Especially when you say it bogs over a wide throttle range. But I still want to believe it's possible.

Re: The ol' non-ethanol gas talk

DrGeorgeTompson (Alan) /

I mean yeah, wouldn't it make the system "up to 10%" leaner running ethanol fuel? obviously not 10% but there is some loss in efficiency.

I found this on a drag racing forum so you know it's legit: "Ethanol requires roughly 30% more for the percentage that's mixed, so with 10% ethanol you would have to jet 3% up, down for ethanol free. depending on the carb size 1-2 jet size should do it." here's the thread if'n you like ta reed: http://www.yellowbullet.com/forum/showthread.php?t=2193538

It's a 19mm PHBG with a jet probably around 100 so i would think it might require a bump in Jet size by 3% or so. Probably more negligible on smaller carbs. I did buy some 90 Non-ethanol a while back and i can't remember if it had any ill effects on my 21mm carbed Garelli. I was always having problems with that dumb shit if it was 5 degrees colder than yesterday so maybe i just didn't notice.

I do notice a change in performance/fueling when changing my premix ratio (less oil tends to run more rich) and that difference in oil is also very small. Not to the point where i get weird bogging and the bike shits the bed or whatever but it is different.

really you are just jetted too rich for E10 fuel and not living on the edge of your seat to begin with. Teeter that bitch on 450* all day like a real man so you can change to non-ethanol on the fly and impress your homies.

Re: The ol' non-ethanol gas talk

I think coincidence, I run non ethanol in my bikes and occasionally have to run regular pump gas. I have a hobbit with basically the same sutup and have not noticed any performance gains or loss.

I run it purely run non-eth for it’s longer shelf life and does not gum up carbs like pump gas.

Re: The ol' non-ethanol gas talk

Ethanol has 2 major differences with gasoline.

1) less energy dense

2) will absorb water, which doesn't burn

Seems only logical that the combination of the 2 will make your moped run cooler, as opposed to ethanol free.

Interesting articleijust read: https://cropwatch.unl.edu/ethanol-and-water-contamination-—-comparing-water-removal-additives

all fuel expires. The more volatile molecules evaporate first. Volatile compounds make yer moped easy to start. is there a date on this stuff you used?

did you measure the oil? too much oil will make yer moped run hotter too. (edited)

Re: The ol' non-ethanol gas talk

> DrGeorgeTompson (Alan) Wrote:

> I found this on a drag racing forum so you know it's legit: "Ethanol

> requires roughly 30% more for the percentage that's mixed, so with 10%

> ethanol you would have to jet 3% up, down for ethanol free. depending on

> the carb size 1-2 jet size should do it." here's the thread if'n you

> like ta reed: http://www.yellowbullet.com/forum/showthread.php?t=2193538

I'm sure it's legit, it's just drag racing is the extreme and different in almost every regard. So I wonder, can a little 2 stroke even benefit from it?

It's like down force and spoilers. The same physics applies to a Formula 1 car and a Ford Pinto. It's almost impossible to drive a Formula car without one, but it doesn't make a lick of difference on the back of a Pinto even though they function exactly the same way on either vehicle.

Re: The ol' non-ethanol gas talk

Well I dumped the gas and added regular gas that seemed to help but then realized my carbs mixture screw was stripped so that could be the issue as well cause my bike has had trouble variating fully

Re: The ol' non-ethanol gas talk

i just use 100LL from the heliport.

no bullshit, always the same, no water, if some it looks like jelly beans and can usually get most out.

but that never happened.

fuck pump gas, asshole gas station had leaking tanks, was all water and dirt when i put in in a clear container.

fuck pump gas.

i run cooler, and can go to 2.0mm on all my bikes.

Re: The ol' non-ethanol gas talk

Crack your pump gas with a litre of distilled water into the jerrycan to overwhelm the alcohol, decant the cracked gasoline from the top of the can for your fuel needs.

Re: The ol' non-ethanol gas talk

Well after changing the gas back to regular I'm still having major issues running. It was running just fine when I brought to my new place. I've adjusted the needle the main jet within 90-100 still fuckin up. I have the right atomizer and idle jet w-7 needle. Still nothing and I feel 80s range is too lo but I do love about 1600 ft above sea level??

Re: The ol' non-ethanol gas talk

May be electrical? If points I would clean and regap. If CDI, try a new box. Also maybe a new HT coil. Worth a shot. Lots of time carb problems are really electrical. (edited)

Re: The ol' non-ethanol gas talk

True I did just swap cdi boxes but it is still on original one from the 80s lol I'll try that

Re: The ol' non-ethanol gas talk

My hobbit it was cutting out at random times. I was being hardheaded and tried 3 CDI boxes with the same result. Got a New HT coil and it has been fine ever since. Hope your peoblem is something simple.

Re: The ol' non-ethanol gas talk

one easy answer: The problem is that pure gas is never pure, and a 10% blend is rarely 10%. That's why the pumps reads: "May contain 10%...". But in reality, it could be 1% or 15%, or any percentage in between. (*)

to set the record straight, energy content is not the same as Stoichiometry. stochi for gas, 14.7, for 10% ethanol, 14.04. huge difference?

Tl;Dr change possible crap gas before fixing something that worked (before a singular? change)

Rebel, you'd better put in the disclaimer about restoring the octane after cracking the ethanol out, as it drops to a lovely 78 or so!

Full Tuck, you wrote "too much oil will make yer moped run hotter too" not derailing, but that's a biased assertion based on what? friction, energy content, flame speed, octane, viscosity, or the tired A/F ratio mantra?

25:1 to 100:1 with a 100 jet could mean a 97 jet? much less with smaller jetting or closer oil ratios.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account