Fuel question

[snow7]

Its probably been asked many times on here but I cant find it. Is it necessary to run a lead substitute in gas on these motors. I usually do but wondering if i need too. I know you should use high octane fuel but it says on all these sleds do not use unleaded fuel. But maybe the newer oils lubricate better so its not needed
Thanks for any info

[JD_Sledder68]

Unless the rings need lead for lubrication, can't imagine that they would since they do not turn around the piston, there aren't any engine parts that would benefit from the lead. Lead was mainly used to lubricate the exhaust valve seats on 4-strokers. 2-strokers do not have the same type of valve as 4-strokers.

Don't take my word on this though, it is just my take on it.

[snow7]

Thats always what I thought too was the lead was for the valves but when I see do not use unleaded fuel on warning stickers on the sled it made me wonder. Maybe leaded fuel was higher octane

[400brian]

Octane is what you need, lead just fouled the plugs.

Unleaded fuel was new, leaded regular was a known commodity. Many of us run premium in our Kioritz powered sleds.
It is closer to the regular available back in the day.

[JDT]

Premium is well worth the extra 20 cents per gallon.
If you can find premium without ethonal so much the better.

[JDGuy]

Unleaded is fine for 2 strokes. Good to run lead subsitute in 4 strokes manufactured before no-lead fuel, assuming it is effective? The lead acted as a valve and seat lubricant. Without the lead that just happened to come with the octane improver, tetraethyl lead, valve & seat life were compromised. This situation was fixed by using better (more expensive) valve material and hardened valve seats. Hardened seats was the more important of the two. In cast iron cylinder heads without seat inserts, the seat area of the head was induction hardened.

[80spitfire]

I'm really glad someone posted about this because I've always been curious about this too.

[AirborneX4Special]

The performance and longevity of any gasoline engine hinges on the octane of the fuel burned because producing energy is simply easier when more of it is available in the fuel. Ethanol in it's current taxpayer subsidized form will never be anything but a glorified solvent that will consume all the moisture from everything in it's path. Modern engines are equipped to deal with the current scenario while older ones are not, so plan accordingly.