Why not run injectors at 100% duty?
Leaving headroom keeps them from running static at peak load and gives the ECU room to add fuel.
ATV Calculator
ATV Fuel Injector Size Calculator
Size injectors from target horsepower, how hard they will be driven, and whether the engine runs gasoline, E85, or diesel.
Results
Values update after you calculate. Empty or invalid inputs will not invent a number.
Enter the values and choose Calculate to see estimates.
How it works
Brake specific fuel consumption is chosen from fuel type. That fuel flow is split across injectors at the duty cycle you enter.
lb/hr per injector = (HP × BSFC) ÷ (duty cycle × cylinders). cc/min ≈ lb/hr × 10.5.
These results are estimates for planning only. They are not OEM specifications, safety certifications, or professional mechanical, legal, or financial advice.
Fuel Injector Size Calculator FAQs
Why does E85 need more flow?
E85 has a higher BSFC, so the engine needs more fuel mass for the same horsepower.
Is this for each injector?
Yes. The result is per injector, assuming one injector per cylinder.
Related ATV calculators
Horsepower Calculator
Estimate ATV horsepower from torque and RPM using the standard 5252 conversion.
Air-Fuel Ratio Calculator
Calculate ATV air-fuel ratio and lambda from air mass, fuel mass, and fuel type.
Carburetor Jet Size Calculator
Estimate a starting ATV main-jet size from stock jetting, altitude, and temperature.
Looking for an ATV after the numbers?
Browse classifieds and rentals, or compare trail destinations before you ride.