05/06/2026
How to Determine Sprayer (Jet) Size – Carburetor Tuning Guide
This infographic explains how to choose the right main jet (for high RPM) and pilot jet (for low speed/RPM):
- Main Jet: Too big = jerky top speed, heavy pull; Too small = bogging, overheating
- Pilot Jet: Too big = jerky, fuel-wasteful; Too small = hard idle, engine stalling
- Spark Plug Check (most accurate method): Chocolate color = ideal; Black/wet = too much fuel; White/dry = too little fuel
- Key Tips: Start with factory size, adjust gradually, keep engine well-maintained, match with exhaust/air filter/bore-up, test and inspect spark plugs after tuning
Goal: smooth performance + good fuel efficiency