Leaded Race Fuel

[Charles_Kaneb]

You can check for oil/fuel compatibility by mixing up a small amount in a plastic bottle and leaving it overnight. Mystik Sea and Snow JT-4 and Klotz Super Techniplate are both JASO FD oils that I know work with both methanol and pump gasoline, while I haven’t seen a fuel yet that Motul 800 separates from. Phillips66 Injex works with both race gas and pump gas but separates from methanol.

[RyanCarag]

@Simone_Perego

Having transitioned from racing X30s in the US to Europe (now living in France), I had the unique opportunity to have my jaw somewhat hit the floor when I’ve arrived for the first time at the track, in Valence, and inquired where I could buy my beloved drum of racing fuel, to which the shop owner promptly replied “Race gas ?? We run the fuel from the pump down the road for all of our official races here”

What? Are you honestly telling me that my two stroke jewel of Italian engineering does not need 112 R/M Octane leaded race nectar refined from the tears of the Gods themselves?

No. In fact, your X30 will run perfectly fine with regular premium pump gas, unleaded, and without any additives or anti knock agents, which have been largely and vastly banned in Europe. This does not only save you money, but it

@Charles_Kaneb

On my new X30, I switched from 110 leaded non-oxygenated fuel to 93, enriched the mixture, and re-tuned on track, then measured how far I moved the needle before getting it correct. It was 15 minutes (1/4 turn) more open on the low-speed jet and 10 minutes (1/6 turn) more open on the high-speed jet. On a Rotax the rule of thumb is 5 jet numbers on the mainjet (from 115 to 120) to compensate for pump gas.

If you are an American track owner and you’d like to get the lead out, go ahead - nothing is likely to go wrong. With this many kids hanging around the pit and driving in tight packs, and studies showing that any amount of lead is worse than no lead, getting rid of leaded fuel can help your image and perhaps benefit your drivers’ health and wallets.

Hi all, sorry to dig this one out of the archives, but this is really useful information for me. So thank you. I’m a kart owner n00b and prepping a new-to-me X30 to run shakedown this weekend. I don’t want to run leaded fuel for all the reasons already stated in this thread.

Charles, if you had a wideband O2 to do the tuning, would you proceed differently?

I will start shakedown and eventually full-speed runs with Sunoco 260GTX 98AKI, E0 hopefully to be close to the E0, non-oxygenated fuel that was run in this engine previously. With the E10 pump gas, there’s both less detonation margin, and some more fuel volume needed, so I could try it with a wideband O2 to have another hard measurements to look in addition to EGT and feel once I work through this pail. Thanks!

[Charles_Kaneb]

The wideband is useful if you want to try it, but you could also go ten minutes richer on each jet and tune by EGT and piston appearance. 93E10 is over 100 RON at good stations in the summer.