Chapter 7
Thread details of the connections on the engines for fuel pipes
• Fuel feed - 11/16" ORFS
• Fuel return - 11/16" ORFS
It is strongly recommended that the flexible fuel pipes, available as an option with the engine are used, which
are as follows:
Fuel feed
The free end of the flexible pipe has a 11/16" ORFS ended fitting, and is supplied with an connector to 1/4"
NPT.
Fuel return
The free end of the flexible pipe has a 11/16" ORFS ended fitting, and is supplied with an connector to 1/4"
NPT.
Fuel tanks should have the following features:
• The filler neck should be raised so that water will not enter when filling.
• The filler cap should seal effectively to prevent water entering when under way.
• A vent pipe should be fitted, again in such a way as to avoid the entry of water.
• The tank should have a sump or angled bottom with a drain tap so that water and sediment can be removed.
(This is not always possible).
• Internal baffles may be required to prevent fuel surge.
• The tank should have a removable panel to simplify cleaning.
• The fuel pipe work should be as simple as possible with the minimum of valves and cross connections, so
that obscure fuel feed problems are minimised.
• The tank should have at least two connections; a fuel feed connection, and a fuel return connection.
Whenever possible a tank should only supply one engine, but in any case each engine should have its own
fuel pipes, from tank to engine.
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