Fueling
Gasoline is an extremely flammable liquid and vapor. Causes skin irritation. May cause drowsiness or dizziness. Store in approved containers.
Fuel & Additives
The FPS Engine is compatible with 91 to 93 octane non-leaded pump gasoline and VP Racing C10 racing fuel. However, on hot days (≥ 100°F / 37°C), it is recommended to use VP Racing Fuel C10 to prevent vapor lock.
Non-leaded fuel is highly recommended. Using leaded fuels will required shorter time between overhauls (TBO) as a result of lead oxide coking on the cylinder and exhaust ports. Leaded fuels will require cylinder, piston, and port, dressing and inspection every 50 to 100 hours (depending on use case).
Regardless of the specific fuel, it needs to be mixed 40:1 with Red Line Two-Stroke Racing Oil. Five gallons of fuel can be mixed with one 16 ounce (473 ml) bottle of Red Line oil to easily achieve the 40:1 ratio. If Red Line oil is not available, an equivalent two stroke oil (2T) may be used.
Additionally, to reduce carbon build-up on the engine components, it is recommended that Lucas Oil Fuel Treatment. Five gallons (19 liters) of gas can be mixed with one ounce (30 ml) of the Lucas Oil Fuel Treatment.
Vapor lock occurs when fuel vaporizes in the fuel lines due to being heated by the engine, climate, or high altitudes. This disrupts the fuel flow and can make starting or restarting the engine difficult, particularly after a hot engine has been sitting for a few minutes.
Fuel & Additives Specs
| Parameter | Specification |
|---|---|
| Fuel Capacity | 72.6 lbs (12.1 gal) |
| Fuel Consumption | ~12 lbs/hr (2 gal/hr) |
| Fuel Type | 91-93 octane or C10 |
| Two Stroke Oil | Red Line Two-Stroke Racing Oil |
| Two Stroke Oil Mix | 40:1 (gas to oil) |
| Fuel Treatment | Lucas Oil Fuel Treatment |
| Fuel Treatment Mix | 1 oz per 5 gal / 30 ml per 19 L |
Gasoline weighs about six pounds per gallon, or about 0.72 kilograms per liter.
Fueling
- Mix gasoline with two stroke oil and fuel treatment.
- Determine the amount of fuel, by weight, required for the flight duration plus an additional 30 minute reserve of gas (approximately 6 lbs or 1 gallon).
- Place the fueler on a scale, on flat ground, and record the starting weight.
- Remove the aircraft fuel cap.
- Dispense fuel until the scale reads the starting weight minus the desired weight of fuel. If the fuel tank is filled completely, fuel will begin dripping from the overflow vent located at the rear right of the fuselage. If this happens, drain a small amount of fuel from the aircraft until the vent stops dripping.
- Secure the aircraft fuel cap.
- Record the fuel weight.
Defueling
- Place the a fuel can on a scale, on flat ground, and record the starting weight.
- Remove the aircraft fuel cap.
- Insert the fuel line from the fueler into the fuel tank.
- On the fueler, toggle the switch to begin defueling.
- As the tank nears empty, the fueler will begin to draw air bubbles through the pump. Keep draining until the fuel line is mostly air.
Never leave the fueler unattended while fueling or defueling. Continuously drawing air through the fuel pump from an empty tank can lead to overheating and eventual seizure of the pump.
- Turn off the fueler.
- Remove the fuel line.
- Secure the aircraft fuel cap.
- Record the fuel weight removed.