Gas mix

[Vti5]

Q What is better to add to gas for old 1010 I have added leaded mix before but have been told Marvel mystery oil is better would love to hear opinions

[Lavoy]

For the most part, I think the only thing that will truly prevent valve seat recession is true tetraethyl lead, my guess is anything else is pretty much snake oil if that is what you are afraid of.
If you have other reasons for using it, then possibly a different story. On any rebuild I do, I have hard seats put into the head, so it is no longer a worry. Not that I have ever worried about it without them.
Lavoy

[Stan Disbrow]

Hi,

I have been running my M and 420 on unleaded gas since they took the lead out. No issues yet. I did wean them off lead once I saw it coming. You know, add 5 gallons of gas, four leaded one unleaded for a while. Then 3:2 for a while, then 50/50, etc.

The whole purpose of lead was to prevent detonation in high compression engines. Which, Deere engines are not. The bad side effect is it builds up on valves and seats. Removing the lead all at once leads to fracturing of the built up lead, with no new lead replacing it. That leads to a gap and fire passing by, which erodes the steel.

Note that gas back when these were built came out two pumps. Methyl and Ethyl. Methyl was always unleaded. Ethyl was leaded. Amoco premium was always unleaded from the beginning thru today. So, these machines were likely run on unleaded from the day they were built. Methyl being always cheaper than Ethyl and farmers being always cheap....

It wasn't until the 1960s that cars were more often than not high compression, and the pumps changed to both being leaded. Lower lead regular and higher lead premium. Except for Amoco. Always unleaded premium. My favorite was Blue Sunoco from the Blend It Pump.

These days, you are better off asking what to add to the Ethanol (and other crap) Not Gasoline you buy.

Me, I mix 100 Octane unleaded racing fuel with 93/94 Octane pump Not Gas. This prevents the detonation I was getting in the old updraft carb engines which was fracturing my spark plug insulators after about an hour of work. And, it greatly helps cold starting as well.

I tried running straight race gas, but it evaporates fast. So fast it ices the carbs up on a humid summer day. So 50/50 works out better. Besides, race gas is currently $7.50 a gallon at the track and close to a buck more at the gas stations which have it (road tax) for the old cars from the 1960s.

The extra cost comes mostly from having to distill the 100 octane from the 93/94 octane base stock at the refinery. Extra steps and lower demand raise the cost, but I find it worth the extra money to run it.

Straight 100 Octane makes for great 2 stroke fuel, too. And it can sit all winter and not go bad. Wonderful stuff.

Stan

[RustAndDust]

I run a 50:1 mix of non-ethanol 93 and two stroke oil.Red Armor two stroke oil to be exact.I don't notice any blue smoke from the exhaust.My theory is that two stroke oil provides a little top end lubrication,as well as helping the valves.I could be wrong,but surely it's better than nothing.

[Vti5]

Thanks for the quick response it is going to be great being a part of this group of jd crawlers : :

[halwelch]

I've heard of folks running 100LL aviation fuel in older engines and small engines. I've been using Marine Stabil on the recommendation of a local small engine mechanic. I mix all my cans at the storage rate since you never know how long it might set especially in something like a generator. I also shut off the gas and let them run dry when I'm done for the day so none of that ethanol stays in the carbs. So far I've had no problems and everything seems to fire right up even after setting for some time.