Ethanol free gas for Knucklehead

[knuckjunky]

Just found a guy near me who sells Ethanol free gas. Says it's 110 octane. Need it for my knucklehead. I want to use the best stuff I can for my machine. Any opinions?

[Jerry Wieland]

I always prefer to run ethanol free gas but the bike runs just as good with the ethanol gas. I just never let it sit with ethanol gas in it because it seems to go skunky real quick and cause corrosion and moisture problems. Your bike does not need that high of octane if it is stock + you will never find that high octane stuff on the road away from home.

Jerry

[rousseau]

What is really needed is leaded gas. I will buy it from "race shops". I then cut it with ethanol free about 4to1. I use this in all my vintage bikes.

[Jerry Wieland]

Why do you need lead?

What is really needed is leaded gas. I will buy it from "race shops". I then cut it with ethanol free about 4to1. I use this in all my vintage bikes.

[rousseau]

http://www.todayifoundout.com/index....d-to-gasoline/

[rousseau]

Another benefit that became known over time was that Tetraethyl lead kept valve seats from becoming worn down prematurely. Exhaust valves, in early model cars, that were subject to engine knocking tended to get micro-welds that would get pulled apart on opening. This resulted in rough valve seats and premature failure. Lead helped fuel ignite only when appropriate on the power stroke, thus helping eliminate exhaust valve wear and tear.

[jwl]

IMHO, the best gas you can find is good for when you store the bike. When you are riding frequently though, a knucklehead will run just fine on 87 octane. Use premium if you like but it is a waste of money. I won't store my bike with ethanol. I don't think the valve wear and tear you are referring to is a problem unless you have antique valves and seats.

[Jerry Wieland]

I agree John - lead is ancient history if you are running new age valves and guides that are readily available. I would not put OEM stuff in a bike even if I never intended to run it.

IMHO, the best gas you can find is good for when you store the bike. When you are riding frequently though, a knucklehead will run just fine on 87 octane. Use premium if you like but it is a waste of money. I won't store my bike with ethanol. I don't think the valve wear and tear you are referring to is a problem unless you have antique valves and seats.

[kval]

In Florida some of the Marathon gas stations sell a 91 octane Ethanol free gas

[rousseau]

[QUOTE=j I don't think the valve wear and tear you are referring to is a problem unless you have antique valves and seats.[/QUOTE]

All of my "antique" bikes have antique valves and seats. I'm guessing that most antique bikes/engines do. Valves / guides can easly be replaced, but it's the seats that take the real "beating". I stand buy my original post. The lack of lead in todays gasoline ,is worse on our old machines than the addition of ethanol.

[T. Cotten]

All of my "antique" bikes have antique valves and seats. I'm guessing that most antique bikes/engines do. Valves / guides can easly be replaced, but it's the seats that take the real "beating". I stand buy my original post. The lack of lead in todays gasoline ,is worse on our old machines than the addition of ethanol.

The bottom line Folks,..

...Is that tetraethyllead and ethanol were both added for the same singular purpose: To increase the octane rating of otherwise poor fuels.

The subjective side benefit of protecting "soft" seats was not the intention of using lead.
H-D had the folly of switching from hard seats to soft in Shovelheads just about the time lead was eliminated, and the "spot-weld" erosion was often apparent to the naked eye.
Incompatible aftermarket valve materials often contributed as well, as some 'stainless' offerings were so high in nickel that they would quickly gall cast iron guides and stick to soft steel seats.
Lower octane fuels led to higher combustion temperatures, and I doubt fuels are much better today.

From my observations at the time, Flattys with integral cast iron seats did not suffer the way OHVs did, even though their temperatures are far more into the "weld" range.
Pans with bronze seats did not show the spot-weld effect either, although they were always 'sunken deep' anyway.

If you do not intend to ride in circles around an airport or a chance ETOH-free station, it is best to outfit your machine to deal with P4gas.

....Cotten

[duffeycycles]

I think flattys are so low compression that they don't ping and therefore don't weld valve to seat-mine will run on anything and no problem with valve/seat wear.But as Cotton says,cast seats may be the diff

[Will]

I use MARVEL MYSTERY OIL all the time seem to make it run better. Dido on not storing with ethanol gas

[AFJ]

Just found a guy near me who sells Ethanol free gas. Says it's 110 octane. Need it for my knucklehead. I want to use the best stuff I can for my machine. Any opinions?

If it is leaded aviation gas (at that octane it could be) you don't want to use it. Apart from the adverse effect of the lead oxide, lead bromide and lead chloride from the reacted and unreacted Tetraethyl lead and tetramethyl lead all of which are bad or corrosive to the spark plug, valve and valve seats the tetraethyl and tetramethyl lead, and the ethylene dibromide and ethylene dichloride (the latter two put in to help get the TEL/TML out of the combustion chamber) are toxic/carcinogenic substances. Same thing if the additive is MTBE (Methyl tert-butyl ether) as found in some car race fuels.
The one thing to remember in using gasoline fuel with ethanol (ethyl alcohol) instead of lead is that while the lead was used to slow the burning of the gasoline in the combustion chamber in order to prevent knock, alcohol is actually both a fuel and an oxygen donor which helps burning of the fuel charge and can improve combustion and engine power. Therefore when using gasoline with a percentage of alcohol, more power and cooler running can be obtained by using a richer fuel mixture and less ignition full advance timing.
In modern fuel-injected, computer - controlled auto and motorcycle engines this timing and fuel mixture are automatically controlled. In our old bikes use of the manual advance/retard ignition lever and the manual choke lever can help determine how much to adjust the timing and what larger main jet could be needed in the carb.

AFJ

[AFJ]

I use MARVEL MYSTERY OIL all the time seem to make it run better. Dido on not storing with ethanol gas

Recently there has been a move to limit the level of sulphur in gasoline. Old motorcycle engines often have fairly minimal valve guide lubrication and the levels of sulphur in gasolines many years ago apparently helped prevent guide sticking problems. But a lot of motorcycle engines made 70-90 years ago run best with a little "upper cylinder lube" or "top oil". There are many brands of this sort of stuff, Bardhal, Redex, Wynn's, etc., and Marvel Mystery oil (basically a 2-weight, or so, light oil with a little "oil of wintergreen" - methyl salicylate - to give it that smell, seems to work well in my 1938 bike. The same amount of a modern ashless 2-stroke oil works well too.

Gasoline with alcohol does not store as well as leaded used to as the moisture in the air is taken up by the alcohol.

AFJ