Nanni QLS 10T, Instruction Manual

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7

Fuel system

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  Warning!  : 

Total  cleanliness  must  be  guaranteed 

when working on the fuel circuit. No impurities must en-

ter the injection pump and the injectors. Carry out each 

of these operations with the engine cold and stopped.

Bleeding the fuel circuit

The fuel circuit is self-priming but manual bleeding is re-

quired after replacing the filter, after have running out of 

fuel or after a work on the circuit if it has been emptied.

• Loose the drain valve screw 

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 on the engine fuel

filter support.

• Pump the priming pump by pressing the button 

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repeatedly until bubble-free fuel comes out of the

drain valve screw.

• Tighten  the  drain  valve  screw  and  lock  the  hand

pump.

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 Caution! : 

Avoid draining all the fuel in the filter when 

venting. If so, remove the filter and replenish with fuel 

before replacing it and repeat the venting operations.

Maintenance

Replacing the fuel filter

This filter treats the water and impurities in the fuel be-

fore it enters the injection circuit.

• Cut the fuel intake at the tank.
• Place a receptacle under the filter and then remove

the used filter 

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cartridge.

• Apply a thin layer of fuel over the seal surface of

the new filter cartridge before fitting it.

• Tighten it by hand until the filter makes contact with

the filter head then tighten it by a half-turn.

• Untighten the drain valve screw to release the air.

Open the fuel valve again and drain the circuit.

• Start the engine and check the assembly is leak-

tight.

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 Caution! : 

Used filters must be disposed of in an ap-

propriate container.

Replacing the fuel prefilter 

The fuel prefilter is an optional component that purifies 

the fuel before it is injected in the engine. These instruc-

tions are given as an example only.

• Close the fuel shutoff valve on the fuel tank.
• Place a receptacle under the fuel prefilter. Remove

the filter tank

• Drain and clean the filter tank.
• Replace the cartridge and re-install the tank.
• Open  the  fuel  valve.  Drain  the  feed  system  then

start the engine to check the leak-tightness.

Draining the water from the fuel prefilter 

Before  starting  the  engine  each  time,  ensure  there  is 

no water in the fuel prefilter. If there is water, place a 

tray under the fuel prefilter and then drain the water and 

impurities using the bottom cap/valve.