S&S Cycle In-Tank Fuel Pump - Manual (Page 7)

7
Fuel Pump Outlet Connection
1. Use SAE 30R12 or other low permeation, high pressure fuel hose to connect the banjo fitting to the fuel rail. It is recommended to temporarily
install fittings for a fuel pressure gauge for initial system testing if the fuel rail does not have a port for system pressure testing. Use either
pinch or bolt style hose clamps. Do not use worm-gear clamps with slits in the metal that could potentially cut the hose.
2. Again, be sure that the final routing of the fuel line will have adequate clearance from hot or moving surfaces and electrical hardware. The
fuel line should clear all rough or sharp engine surfaces to avoid chafing. The line should have at least one bend to allow for relative motion
of the engine with the tank.
3. For best results, S&S suggests the use of a high pressure (at least 70 psi continuous), 10 micron filter on the outlet end of the pump. Often, if
the fuel system was not adequately cleaned, small particles will pass through the fuel inlet filter and pump. These particles then plug the inlet
screens of the injectors and result in poor running conditions.
Initial Startup
1. Pour a small amount of gasoline in the tank. Be sure to add enough fuel that the inlet filter is submerged.
2. Turn power on and check for leaks. If used with an S&S control system, the pump should operate for 2 seconds and shut off.
3. Add more gasoline. Check the fuel pressure with the pump running. The pressure should be 58 ± 2 psi (400 ± 8 kPa).
4. After the pump turns off, the pressure should hold at least 43.5 psi (300 kPa) for five minutes.
5. Start and run the motorcycle. Again monitor fuel pressure.
6. If available, it is recommended to run the motorcycle on a dynamometer while monitoring air fuel ratio and system pressure, especially at
wide open throttle.
Calculating Reserve Fuel
If using the low fuel indicator, you may want to determine the approximate amount of reserve fuel available in your installation. Below is one
method for doing this:
1. With the motorcycle upright on a level surface be sure enough fuel is in the tank to completely immerse the inlet filter in fuel. You may need
to use a small mirror and flashlight to view this.
2. The low fuel indicator should illuminate with the ignition switch on. Add more gasoline until the low-fuel light turns off. Note the amount of
fuel used. This is the reserve.
Troubleshooting
1. The fuel pressure drops off when running Wide Open Throttle on a dyno:
a. Be sure that your battery and charging system is in good condition. Be sure that the system voltage is 13.2 volts or greater when running
in this condition. It is best to verify system voltage at the fuel pump connector. This will ensure there are no voltage drops in the wiring,
switches, or relay causing the problems.
b. Be sure inlet filter is not clogged. If in doubt, replace it.
c. If an in-line filter is installed on the pump outlet, test pressure on both sides of the filter to determine if it is clogged.
d. Review system flow rates and fuel requirements. Be sure the pump is not too small for your system.
2. The motorcycle is running lean or misfiring.
a. Be sure the injector inlet screens are not clogged. It is recommended that you remove the injectors, let them dry, and tap the inlet end
of the injector to loosen any debris that may have adhered to the injector screens. If it appears that they are clogged or if in doubt, it is
recommended that the injectors be cleaned by a shop with professional injector cleaning equipment.
b. Verify that the system pressure is correct and the correct calibration is being used.
c. Check for intake leaks.
d. Ensure that you have adequate spark and troubleshoot other electrical systems.