Stupid Simple Small Engine Fuel Injection System

Basics

• S3 EFI
• An Electronic Fuel Injection System Developed by Robot Cantina (YouTube Channel) / Jimbo that is based off of the Bosch CIS System
  • It is somewhat in-between a “dumb” Carburetor system, and a modern “smart” system like a Speeduino with tons of sensors / Dual Injection etc
• Low Complexity/Points of Failure, but just smart enough to work reliably is the design goal
• As per3:36 in the video,
• It DOESN’T HAVE:
  • A Crankshaft Position Sensor
  • A Throttle Position Sensor
  • An Air Intake Temperature Sensor
  • Oxygen Sensor
    • This MAY be useful enough to add in in their opinion
• It DOES Have:
  • A Manifold Absolute Pressure Sensor
  • A Thermal Time Switch ( Thermal Fuse ? ) for Cold Start detection+adjustments
  • A Delay Based Startup Enrichment

Components

Fuel Pump

• An Amazon Listing for the Kohler EFI Fuel Pump Module ( ~57 USD as of this edit’’’ )
  • As per 5:38 in the video, you are not supposed to gravity feed these pumps
  • It needs a Diaphragm Pump based low pressure pump to go from fuel tank to it’s low pressure fuel inlet

Fuel Injector

• An Amazon Listing for “GY6 Clone” ( ‘’’~28 USD as of this edit’’’ )
  • ” Perfect Fit: Designed as an OEM replacement, this RedCap fuel injector provides a precise fit for Jonway GTX 250, Cougar Cycle Clash Force 200 EFI, Gator 200-Tank, and other scooters or motorcycles with XMT 250 EFI GY6 168cc, 170cc, and 200cc engines, ensuring seamless integration and reliable performance.”
  • Mentions EV1 Fuel Injector style wire connections?

Electronics

• Arduino Uno
• Relay for Fuel Pump
• SSR for the Fuel Injector
• Potentiometer/Hall Effect Knob for AFR Trim
• E-Stop

External Links

• A Video by the YouTube Channel “Robot Cantina” Titled “S6 Ep8 We build a simple fuel injection system for the 212cc Predator ( ‘’’~30 Minute Watch’’’ )
  • Mentions the 212cc Predator Engine