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Fuel Flow Meter

It would be great to a have a means of measuring fuel flow. This would enable me to test the oil/fuel ratio at different throttle positions. A permanent one would also allow you to work out how effieciently the engine was running and how long your fuel would last for the speed (it also might be useful for aerodynamic measurement).

Here are some notes:

Fuel flow is measured with a Fuel Flow Transponder. These work for various rates (e.g. 2.5-150 litres per hour Navman 2100 Fuel)

Quick Calcs:

A Vespa running full throttle on the highway will use a tank (~7.5 litre) in about 130Km. The top speed on the open road (as measured by a GPS) would be about 100Km/hr. The Vespa manual has an optimistic 260Km on a tank and I think this is at 60Km/hr.

Full Throttle Flow Rate = 7.5 litre in 1.3 hours = 5.76 litres an hour
Vespa optimistic Flow Rate = 4.33 hours = 1.74 litres an hour

So an ideal transponder would be 0.25-15 litres per hour.

Flow Meters

Remember ideal flow rate 0.25-15 litres per hour. We are expecting about 3-6 litres an hour for highway use.

 Navman 2100 Fuel 2.5-150 litres per hour

Flowscan 20B Gasoline Sensor exact rate/accuracy not specified but the Series 55000 Cruisemaster gauge can be bought with a 0-40 LPH range.