What fuel octane do you use?

Simon King /

I almost always fill up with the highest octane that I can find. Some people claim that the higher octane can be bad for the engine though - saying that it runs too hot and crauses long term damage even if the short term makes you go faster?

What is your opinion/experience on the significance of this?

RE: What fuel octane do you use?

98 octane myself. The more, the better (some engines can knock on low octanes).

RE: What fuel octane do you use?

i have always use 87 octane on my ped

RE: What fuel octane do you use?

Reeperette /

Runs hotter ? what are they smokin ?

Higher Octane = Lower burn temp, less crud.

Now some peds are designed with a higher burn temp in mind, and using a high octane fuel with one of those will produce insufficient temp to properly vaporize the mixed oil, and you get more crud than with a low octane, etc..

And two 'peds, ostensibly of the same make, can run best with wholly different fuel, so it's more a matter of trial and error, and finding your own 'peds idiosyncracies.

Best way to start guessin, is check your plugs operating temperature.

Ree.

RE: What fuel octane do you use?

One thing to consider is that if you ride 2000 miles in a year...... running on premium will only cost $10 more than regular.......for the whole year.

In the US our available octanes are ...87...89... and 92. (racing

...105, 110, 120,and Avgas 100LL avail. also)

Twowheelers doesn't live in the US ( I think) and European octane measuring system is different from ours.... their 98 is like our 92 or 94 (or close).

Octane is a measurement of a gasolines ability to resist pre-ignition.

Pre-ignition is a gasoline 'lighting off' before the spark plug even fires because it is too volatile and will "explode" at a combination of heat and pressure alone (with no spark) like a diesel engine does (diesels have NO spark plugs or ignition systems)

Pre-ignition is also known as "knock", or "spark knock" and also "pinging".

An engine that is pinging will steadily (and quickly) get hotter and hotter till something melts (piston crown) or seizes.

So higher octane means you can run higher heat and compression without getting pre-ignition..... this is why high performance engines need higher octane and ping badly with low octane.... higher octane allows engines to be tuned for more HP without damaging themselves.

Which brings us to mopeds.... mopeds are low performance engines (in US) designed for simple cheap transportation.... they are not high performance and do not need high octane.... high octane will not hurt a ped engine (or any engine) there is just really no point.

One thing to remember is that mopeds are quite often ridden by kids... who might just put any gas in anything.... the engineers know this and make a moped so that it will not hurt itself with the lowest octane available.

But if you feel yours runs better with premium.... thats alright.. it'll only cost bout $10 more for a whole year of use.

I don't believe there is any more or less crud or dirt in any of them... they all get processed by the same equipment, trucks, and storage tanks..... a $2 inline plastic fuel filter is smart for any small engine.

RE: What fuel octane do you use?

SIMON, I was in the service station bussiness for many years and the only difference in the gasolines (major brands) is the addatives!! You have 1 pipe line running into a terminal, everything comes thru it, at different times, gas-diesel-heating oil. I was with PURE OIL CO. and the driver dumped a load of regular gas into the hi-test tank about 5,000gal and he called in and they sent a guy out with a couple of 5gal buckets of addative...all is well. But now, with the new rating system, the hi-test is not much better than the old regular. We have these little gas squeesers (HA!) why not get close to the older specifications,...and use HI-TEST, it`s bad enough. Later Dude.....DOUG D.

RE: What fuel octane do you use?

SIMON, I was in the service station bussiness for many years and the only difference in the gasolines (major brands) is the addatives!! You have 1 pipe line running into a terminal, everything comes thru it, at different times, gas-diesel-heating oil. I was with PURE OIL CO. and the driver dumped a load of regular gas into the hi-test tank about 5,000gal and he called in and they sent a guy out with a couple of 5gal buckets of addative...all is well. But now, with the new rating system, the hi-test is not much better than the old regular. We have these little gas squeesers (HA!) why not get close to the older specifications,...and use HI-TEST, it`s bad enough. Later Dude.....DOUG D.

RE: What fuel octane do you use?

I'm using the lowest grade available -- it's 80 but I think I could run on 92 as well. If anyone knows, the octane selection depends on the compression ratio of a particular engine. I've once explained this earlier in this forum, so those of you who are interested can search for it. My compression ratio is 8.5, so it's in between the 80 and 92 grades, and if you decide to change from lower grade to a higher one, you need to retard the ignition timing because higher octane gas burns faster. And likewise, if you start to get filled with a lower grade, the ignition needs to be set earlier to prevent knocking. Anyway, search for the earlier discussion and get more info there.

RE: Daniel answer<>

ANSWER FOR DANIEL, this would go back to the year of the bike....using the new or old octain Rating?? BUT... if this is a concern... the synthetic oil now would provide good lubrication even if the gas does have a quicker flash point w/o loosing performance by lowering timing....ie: racing bikes ....Like in race cars, use highest octane you can get and a ignition timing of full advance of 40 deg.+ with moderate temperature....later Doug

RE: What fuel octane do you use?

I personally run 110 octane in my goped, my 200cc blaster (with 104 octane booster) and in my gaddabout.

Sometimes in my Subaru to, but it dosent like it all the time, heh.

RE: What fuel octane do you use?

HI- test from major brands, use the AMSOIL 100:1 mix synthetic oil. This will work in my 2 strokes thats call for--40:1, 25:1, 16:1 ratio. and top this off with a recomended dose of Sea Foam carb and system cleaner that contains a stabalizer. My 5 mopeds and 2 motorized bikes, weedeater,chainsaw all run better than new out of the same jug.!!!!

hey ping on moped

i got a new moped and when it is idling it knocks like it has a rod knock but the thing has 1000 miles on it.i know this is is not the pison because this is louder than a piston knock.. i have a moped with piston knock so i know. as the revs get hgiher the ping goes away. i run the low grade in it and i was wondering if i should use the high grade...... the compression ratio is 9:1...kinda high. so any answers would be apreciated.

RE: hey ping on moped

Gary Trezza /

Experiment with a good premium fuel, then, PER GALLON: about 1 oz. octane booster, no more than 1 oz of a gen. purpose carb cleaner/ stabilizer, 4 to 5 oz. good quality 2-cycle oil, (NOT outboard motor 2-cycle), and for pre 1975 peds, 1/2 to 1 oz. lead additive. This potion has run all my mopeds and gopeds to perfection for 25 years. Remember, only use the lead additive only for OLDER mopeds. Check your plug after 15 or 20 miles, the color and lack of oil or other deposits will show you how you are doing. It should be a dry but chocolate brown color with no wetness or deposits. Adjust your potion from there, if necessary. GARY.

voodoo witches brew

Your potion has NO REAL BENEFIT for low compression mopeds (except the cleaner/stabilizer)

Premium gas

...Not necessary... Mopeds are LOW compression, they don't need premium

Octane booster.

...Not necessary... if a moped doesn't need premium, it doesn't need an even higher octane.

Carb cleaner/stabilizer

...OK.... maybe twice a year... particularly during winter storage.. and once a year in summer to keep deposits forming.

Lead additive

... Not necessary... lead serves no purpose whatsoever in a 2-stroke... it's not

even needed in 4-strokes made since about 1967.

If an engine doesn't 'ping' on regular, then higher octane SERVES NO PURPOSE.

P.S..... If a 2 stroke moped manual says the engine has a 8.5 to one compression ratio..... that is the UNCORRECTED comp ratio... the corrected comp. ratio is about 6.5 to one... because the corrected comp ratio is figured from exhaust port closing... if the ped has a Bi-Turbo pipe on it, it will raise the corrected comp ratio a little.

If I run

RE: voodoo witches brew

YEP, There is a lot in what you say, the lead is only a lubercant (older gas) but you are adding a lubercant in a 2 stroke. the unleaded gas uses different compounds for lubing. But the gas today using the -RM-octane rating is a lower quality product, so why not spend another .30 gal for a little closer to original product?

RE: What fuel octane do you use?

Daniel..... you say you are using 80 octane?... where do you get that?.. not in the US... read the pump... it will say 87 octane.

One other thing..... Are you trying to say that the comp ratio number translates directly into the octane number?

........Like 8.5 to 1 means you should use 85 octane?

.........and 9.5 to 1 ................................ 95 octane?

.......and 10.0 to 1.................................100 octane?

....... .or 7.0 to 1 ..................................70 octane?

Because if you are... that is nonsense... the 2 numbers have no relation whatsoever.

The compression ratio is the ratio of trapped air in the cyl at BDC and TDC

The octane rating is the percentage of octane (a hydrocarbon molecule) in the fuel... So 92 octane gasoline contains 92% octane and 8% other molecules.

My 600 Honda has a comp ratio of 11.5 to one... and it runs great on pump premium.... (92 oct).... it doesn't need 115 oct.

But higher comp does mean you need higher octane... not at that direct number conversion though.

Used to be?

Yeah it is pretty cheap...... Doug.... how long ago did you sell gasoline?... and can you remember what the octane number for reg used to be say back in 1970 or so?

RE: Used to be?

Hey Fred, that was back in what some people call the STONE AGE.... when we had gas wars! gas as low as cheap as 15 cent a gallon (PURE OIL CO) and when you got a mouth full of that gas you knew the difference, it would just about make your mouth raw. But the octane rating system has changed, with the gasoline. I am not well educated, to know all the fancy TECK STUFF I have seen here, but I know what I`m saying about gas, so far everyone is correct for the most of it, what works for me might not work for you, If a man feels like adding lead substitute helps him, GREAT, it wont hurt a darn thing but your pocket.....KEEP ON PEDDIN! DOUG OF VA.

RE: voodoo witches brew

Gary Trezza /

Here in the often cold northeast, a higher octane gas certainly DOES help the 2 cycles to fire up, especially after occasional layoffs of several weeks, its easier then emptying the tank and cleaning it every time you rest it for awhile. A lousy little capful of carb cleaner per tank or so is called PREVENTIVE MAINTENANCE. Cost Factor is minimal, as I have saved $$ on spark plugs, I've NEVER had to de-carbonize, etc. On top of that, it's hard to argue with 25 years of practically TROUBLE-FREE 2-cycle service from 4 different bikes/go-peds. YOU CAN'T ARGUE WITH SUCCESS>>>my mix WORKS...

RE:GARYS SECRET BLEND!

GARY, EXACTLY WHAT I`m TALKING ABOUT, this works for you, But would not benifit MR. JOE SMITH in Florida.....GUYS, I think we have LIFTOFF! Doug

SIMON STARTED THIS AND LEFT-n/m

THANKS SIMON, You started this and went on siesta

RE: voodoo witches brew

Shoot Gary... I'm just mad you gave the same secret recipe I use to EVERYONE ELSE

Only I add 2 teaspoons of Peppermint Schnapps and a pinch of nutmeg.. then I face Mecca and bow 17 times while counting backwards in pig latin.

And that works BETTER..................HAW !!

RE: voodoo witches brew

Gary Trezza /

Doug- Judging from Fred's useless sarcassim, I guess he's packed it in, too!Fred wrote:

>

> Shoot Gary... I'm just mad you gave the same secret recipe I

> use to EVERYONE ELSE

>

> Only I add 2 teaspoons of Peppermint Schnapps and a pinch of

> nutmeg.. then I face Mecca and bow 17 times while counting

> backwards in pig latin.

>

> And that works BETTER..................HAW !!

Bigfoot and Nessie

Well I gave you the truth.. but a lot of people would rather believe in Bigfoot

By the way, I did agree with the cleaner/stabiliser... not every tank though (for me)

You know when I saw Simon's question, I wondered if he was having fun by stirring the pot.. and I do believe he was.. he's probably laughing his butt off now.

Oh.. and if I bow 117 times... my moped will do double jumps like Jeremy McGraff.!!

RE: SIMON STARTED THIS AND LEFT-n/m

Simon King /

I'm just sitting back and learning from the discussion - I've decided I'll just keep putting in premium, since it doesnt' cost that much more and I've always had good performance with it -- but i'm not going to bother with finding racing octane or anything.

I'm thinking that the quality of the oil that I use is probably more important than the octane of my gas.

RE: Bigfoot and Nessie

FRED:: This forum is supposed to be the free and open discussion of ideas and OPINIONS. Doug's quote that what might work for one is not necessarilly so for someone else, is absolutely correct. Your Holier than thou attitude that you are right and others are nonsensical is repulsive. I was posting MY OPINION, as others were. The majority prefer to use Premium fuel. If that is somehow against your religion, it is a personal decision. No Need to denegrade others whose opinions differ from yours. There ARE variables in life. This will be my last post on the subject, As I feel I am now contributing to the denegration of this fine forum as well, and that was not my original intention. Have A Nice Life.

Science,,, not opinion

Is it a matter of opinion how many wheels there are on my truck?

Internal combustion engine science and engineering resolved most mysteries regarding octane years ago.

And I have spent most of my life studying, repairing, and modifying small engines... so I do know what I am talking about..(and there is more mis-information in the world than there is information)

Go here and read the quote in article ..7-10....stating that.. "wintertime temperatures allow the useage of LOWER octane"

......... http://www.faqs.org/faqs/autos/gasoline-faq/part3/

Everything you ever wanted to know about octane and ANYTHING related to gasoline in engines is explained in a fantastic manner there.

compression ratio

ignition timing

temperatures

chemistry

history

government

pollution

I regard misinformation presented as fact to be repulsive..lets get smarter.. not believe old wives tales

RE: What fuel octane do you use?

Ha! That was just another piece of shocking news from Russia! As you may know, there are two methods of defining the octane rating -- the research method and the engine method (or motor method), and therefore the values differ depending on the method used. Basically, the values obtained by the research method are higher than these of the engine method. In Russia we have 76, 92, 95 and 98 types of gas on sale, the first of which is defined by the engine method and the rest by the research method. I find it pretty confusing when compared to your ratings but most of these values correspond to the European ones, I think.

RE: What fuel octane do you use?

I only use 80 proof vodka in my ped. Absolut Snark! That's where it's at. Though I've heard some Puchs prefer Yaegermeister ...

RE: What fuel octane do you use?

Still joking, eh, Miguel? You can fill your tank with either ethanol or methanol like those guys at drag racing top-alcohol class. You bike will go furious, I promise. So your joke is not far from reality. We once added some propanol into another guy's fuel tank and he couldn't figure out what happened to his sluggish crawler -- it would rush around like a crazy machine...

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