Fuel System; Fuel Tank Position; Fuel Line; Fuel Valve - Honda GX630 Technical Manual

GX630 • GX660 • GX690 Technical Manual
F S
UEL YSTEM
This engine is supplied with an incomplete fuel system (no fuel tank, no fuel hose, etc.). As such, the OEM is
responsible for ensuring evaporative emission regulations are met.

Fuel Tank Position

The fuel tank must be installed so that its maximum gasoline level is within 50 cm (19.5 in) above or below the
carburetor gasoline level.

Fuel Line

Use a low permeation fuel line (displaying an Executive Order number) rated for use with gasoline. The fuel line should
have an inside dimension of 5.5 mm (0.22 in). Keep the fuel line as short as possible. Install the fuel line so it will not
rest against any sharp objects or make sharp bends that can restrict the flow of fuel. If the fuel line passes through an
enclosure wall, protect the line with a rubber grommet. Secure the fuel line with the appropriate clamping mechanism.
Route the fuel line away from hot engine and exhaust system components and away from electrical wiring. Secure the
fuel line to prevent sagging and bending.

Fuel Valve

Install the fuel valve so it is easily accessible. Install the fuel valve at the outlet of the fuel tank and use an easily read
label to indicate valve location and operation. If under the fuel tank is not the ideal location, securely install the fuel
valve in-line with the fuel tube in a cool location, so that engine heat cannot cause vapor lock.

Fuel Pump

2
A fuel pump should be selected that provides an operating pressure of 0.1 kgf/cm (1.4 psi) and delivers 15 liters/hr
2
(4.0 US gal/hr). The carburetor inlet float valve has a closing pressure of 0.2 kgf/cm (2.8 psi). If a secondary fuel pump
is used, its operating pressure must not exceed the standard fuel pump's operating pressure (to prevent carburetor
flooding).

Fuel Tank Filter Installation

It is recommended that a fuel tank strainer with a mesh rating of #80 be installed at the fuel tank inlet to catch debris
when refueling. It is also recommended that a fuel tank sump be provided at the fuel tank outlet to reduce the chance of
contaminants entering the fuel system.

Fuel-cut Solenoid

The fuel-cut solenoid on the carburetor takes power from the battery and there is continuity in the solenoid when the
engine is running. Removing the battery when the engine is running will cause the engine to stop.
C
ONTROLS

Engine Switch

Use a three-position engine switch with continuity between its terminals as shown.
Wire (Color)
IGN GND BAT LO ST
(Bl) (G) (W) (Bl/Y) (Bl/W)
Switch Position
OFF
ON
START
7
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