Average fuel tank capacity/run time

Looking for input on fuel capacity versus run time on various 13 hp clones or similar powered setups.

Trying to decide what size fuel tank size I need.

Thanks all

I'm probably wrong on this but I have always thought that is an engine is a 500cc, then wouldn't it use 500cc or 500ml of fuel per hour with no load at max rated speed? Is this true?

If this is the case then have a look at the engine size and calculate it from there based on how long you want to to run for.

Like I said, I'm more than likely to be wrong about this.

thanks, but, I already discovered that a custom fuel cell is my only option. there just isn't the space.

Probably the best option, theres a million different tanks sizes on tractors - finding one would be an issue. What about using a washer jug off a car from a junkyard or something similar ?

The space I have available is limited, i may have to run 2 small tanks

The 500cc rating is the displacement of the cylinder(s).

By what I know a small motor like B&S, koler, ect at 3600 RPM use a gallon a hour give or take, my 11.5Hp B&S uses a little over a gallon a hour.

TheRainbowBoxer wrote:

The 500cc rating is the displacement of the cylinder(s).

Indeed but does it have have anything to do with the amount of fuel or air the engine would suck in as well?

CornishMorgan wrote:

TheRainbowBoxer wrote:

The 500cc rating is the displacement of the cylinder(s).

Indeed but does it have have anything to do with the amount of fuel or air the engine would suck in as well?

Only in the sense that the bigger the displacement, the more air and fuel it needs to run,

Chopperhed wrote:

CornishMorgan wrote:

TheRainbowBoxer wrote:

The 500cc rating is the displacement of the cylinder(s).

Indeed but does it have have anything to do with the amount of fuel or air the engine would suck in as well?

Only in the sense that the bigger the displacement, the more air and fuel it needs to run,

Ok so a 500cc would not use 500cc of fuel per hour or 500cc of air?

Nope, I don't even know how much liquid 500 cc is, haha.

CornishMorgan wrote:

Chopperhed wrote:

CornishMorgan wrote:

TheRainbowBoxer wrote:

The 500cc rating is the displacement of the cylinder(s).

Indeed but does it have have anything to do with the amount of fuel or air the engine would suck in as well?

Only in the sense that the bigger the displacement, the more air and fuel it needs to run,

Ok so a 500cc would not use 500cc of fuel per hour or 500cc of air?

Sorry, no

An engine will use the fuel and air required to reach a specific ratio in the combustion chamber. Usually about 14.7:1 ( air to fuel). Chemically, this ratio is called the stoichiometric ratio, and varies. Altitiude, air density, temperature, humidity, etc change the ratios slightly, but the ratio is usually pretty close to the 14.7:1 at sea level.

Increasing the displacement of the engine, increases the amount of fuel and air neccessary to meet the ratio. Changing the airflow of the engine also affects this. So anytime we change a carb, exhaust, or anything related to these two systems, the carb has to be rejetted/reset accordingly. Aircleaner mods ,and exhaust stack are included in this.


Ok, so that being said. these little engines are generally set to run pretty rich anyway. A rich mixture eats gas, but the extra fuel helps cool the engine. Its hard to kill a motor by running it rich, but if you lean it out too much, you get burnt valves, broken rings, and holed pistons. Increasing airflow leans out a mixture, so running stacks and free flowing airfilters will cause issue if its not corrected.

Chopperhed wrote:

CornishMorgan wrote:

Chopperhed wrote:

CornishMorgan wrote:

TheRainbowBoxer wrote:

The 500cc rating is the displacement of the cylinder(s).

Indeed but does it have have anything to do with the amount of fuel or air the engine would suck in as well?

Only in the sense that the bigger the displacement, the more air and fuel it needs to run,

Ok so a 500cc would not use 500cc of fuel per hour or 500cc of air?

Sorry, no

An engine will use the fuel and air required to reach a specific ratio in the combustion chamber. Usually about 14.7:1 ( air to fuel). Chemically, this ratio is called the stoichiometric ratio, and varies. Altitiude, air density, temperature, humidity, etc change the ratios slightly, but the ratio is usually pretty close to the 14.7:1 at sea level.

Increasing the displacement of the engine, increases the amount of fuel and air neccessary to meet the ratio. Changing the airflow of the engine also affects this. So anytime we change a carb, exhaust, or anything related to these two systems, the carb has to be rejetted/reset accordingly. Aircleaner mods ,and exhaust stack are included in this.


Ok, so that being said. these little engines are generally set to run pretty rich anyway. A rich mixture eats gas, but the extra fuel helps cool the engine. Its hard to kill a motor by running it rich, but if you lean it out too much, you get burnt valves, broken rings, and holed pistons. Increasing airflow leans out a mixture, so running stacks and free flowing airfilters will cause issue if its not corrected.

Right, now I get it. Thanks for clearing that up .