🔧 Rotax 125 MAX Senior EVO (2024+) – Main Jet Size Chart with Tuning Tips

Jetting is one of the most important factors in getting peak performance and reliability from your Rotax MAX engine. The 2024+ EVO engines come with a revised cylinder head and are delivered with a stock #130 main jet. Below is a complete chart to help you tune your kart based on weather, altitude, and performance feedback.

🔧 Rotax 125 MAX Senior EVO (2024+) – Main Jet Size Chart with Tuning Tips

🧠 Jetting Symptoms & Adjustments

When tuning your Rotax engine, your kart will tell you what it needs. Use these symptoms to decide whether to go richer or leaner.

✅ Tips for Trackside Jetting

• Always jet for the worst-case scenario — it’s safer to be slightly rich than too lean.

• Use a temperature gun or your MyChron water temp sensor to monitor optimal temps (~140–150°F).

• Perform plug chops after full-throttle runs to confirm your jetting is in range.

• Keep a full jet case with sizes 124 to 136 to adapt to any weather conditions.

Have Questions? Get in Touch

Need more details on engine rebuilds, maintenance, or karting resources? Contact Nashville Karting Group for expert advice and support. We're here to help!