Just a curious question?

[jet1959mo]

I found out through some of the moderators here when my 71 was built.
So, leads to my question.
Since my CCT was built in 66', the label on it says Unleaded gasoline and if I remember right, the manual also. I remember way back, unleaded gasoline didn't become available or was mandatory in vehicles till the 70's.
Why is there such a label on this early garden tractor?

[PaulS]

Both of my 102s were built during the same timeframe and I do not recall any remarks concerning unleaded gasoline on either of them. On page 6 of my operators manual It states to "Fill the fuel tank with clean, fresh, regular grade gasoline, preferably at the end of each days use." My owners manual is for the 71, 102 and the 122.

[Petrus]

Do you have a picture of the label? Maybe the part that the label is on was replaced at a later date.

[Loganvilledude]

I just looked at one of my operator manuals for the 1000-1650 Tractors. I know this is a little later than your model, but this one says>

This engine is designed to operate on leaded gasoline with a 93 minimum octane rating or on unleaded gasoline with a 91 minimum octane rating. It goes on to say that the unleaded gas will increase spark plug and valve life, maintain engine performance longer and reduce rust and corrosion of the engine while stored. Publication 8-77.

The Kohler service manual I have which covers engines K91-K341 suggests unleaded gas 87 octane and higher. It goes on to say using leaded gas will require more frequent service on the cylinder head. Publication 4/90

So with that being said have others on this board had better experience with higher octane gas?

[JayJay]

Originally Posted by Loganvilledude

I just looked at one of my operator manuals for the 1000-1650 Tractors,

"This engine is designed to operate on leaded gasoline with a 93 minimum octane rating or on unleaded gasoline with a 91 minimum octane rating. It goes on to say that the unleaded gas will increase spark plug and valve life, maintain engine performance longer and reduce rust and corrosion of the engine while stored." Publication 8-77.

The Kohler service manual I have which covers engines K91-K341 suggests unleaded gas 87 octane and higher. It goes on to say using leaded gas will require more frequent service on the cylinder head. Publication 4/90

LoganvilleDude: Hum . . . It seems the IH engineers and the Kohler engineers were on two different wavelengths.

I remember owning a 1973 Pontiac which had a filler neck for leaded gas, but hardened valve seats for unleaded gas. The seats were hardened --no inserts; and the owner's manual discussed the fact that unleaded gas would not DAMAGE the engine. I've heard of engines requiring service to install new valve seats to run the unleaded gas. At the time, the loss of lead in the gas was generally viewed as a LOSS, not a gain.

Personally, I run 93 octane simply because it is cleaner. I have never heard of IH recommending it. In fact, I've been shouted down in other forums because it was viewed as overkill.

The "scientists" will tell you that premium grade fuel is designed for higher compression engines and actually burns slower, the thought being that 87 octane is "better" for the relatively low compression Kohler engines. Their argument is buttressed by the contention that the slower burning fuel will result in greater carbon buildup in the combustion chamber.

But I'm not convinced. I feel that the more highly refined fuel will yield a more CONSISTENT burn. Even the "regular" guys admit to using additives, some of which function to increase the fuel's octane rating.

As far as the storage of fuel goes, I've always thought that premium held up better than regular, but the fact is, all the discussion of 87 octane versus 93 octane ignores an even bigger fuel factor which has developed since the 1970's --the use of ethanol (alcohol) in gasoline in concentrations approaching and equal to 10% by volume. The alcohol content destroys fuel lines, gums up carburetors, attracts water and generally wrecks havoc with fuel systems, and makes it almost impossible to effectively store fuel from one season to the next.

Again, I've gone to Premium (93 octane) for my air-cooled engines and I add Marvel Mystery Oil or Lucas Gasoline Treatment or Sea Foam (if I suspect gumming up), and I try to run the engine dry at the end of the season. Since I've been doing this, I have not had to rebuild a carburetor on any of my equipment (knock on wood).

[ploughboy]

It is my understanding that gas is gas til it reaches the distribution terminal. This is where the additives and cleaners above federal standards are added and makes the difference between brands. I do know that in the area of NC that I live all gasoline comes in on the same pipe line and the different brands pick up at the same place.
As for the ethinal, we are able to get and store non blended gas for our out door eq. I personaly use sta bil and marvel mystery oil on eq. that sits more than it is run, and turn off fuel till it runs out of gas. Very few if any problems with storage that way.

[JayJay]

jet1959mo: A final thought, unleaded gas was always available from Amoco, it was known as "white gas". We bought it in the 60's for use in our Coleman camp stoves and lanterns, before Coleman fuel became widely available. The lead in "regular" gas was supposed to crud the burners up. So "unleaded" fuel was available when your Model 71 was built.

I'm sure the Amoco premium gas (93 octane) was unleaded, I'm not sure about their other grades.

I've heard the same thing as Ploughboy from people in the business about how all the gas in a geographic area is derived from the same distributor regardless of brand. The reason all the gas prices are roughly equivalent in a given area is because it is all supplied from the same place.