North&Wing&S,LSA&Maintenance&Manual&
Model:&Sport&X2&582&
Issue 3.2
Printed: July 16 2017
Page 80
4.4# Fuel#System#Repairs#
The fuel system schematic is shown below. The fuel tank is a 15 gallon polypropylene tank
designed to straddle the root tube. An aircraft style drain valve allows removal of a sample of
fuel to assure no water is present in the tank. An equalizer line, located slightly above the
bottom of the tank to avoid picking up contaminants, balances the level of fuel in the left and
right halves. The fuel supply to the engine is taken from the equalizer line with a tee in the
line.
A squeeze bulb primer pumps fuel into the fuel pump, lines, and carburetor float chamber. Its
internal check valve was intended to prevent fuel from running back into the tank when the
engine is not running. However, due to reports of check valve failures in the industry, North
Wing uses a bulb by-pass to assure fuel flow passage to the engine when it is running even if
the check valve does fail closed. This by-pass will allow some fuel to drain back to the tank
when the engine is shut down. Therefore, the bulb should be pumped until firm by pinching
off the by-pass line and squeezing the bulb several times until firm before each engine start.
This is a small inconvenience for the added safety of the by-pass line.
The fuel pump is a standard Mikuni dual pump driven by a pulse line from the pulse port on
the Rotax 582 engine. The pump has two separate outlets to feed each carburetor.
The fuel lines are
¼
” alcohol resistant urethane tubing with clamps or wire wraps at both ends.
The pulse line is standard
¼
” pulse line which is heavier than the fuel line to transmit pressure
pulse with little loss in pressure.
Drain&Valve&
Fuel&Pump&
Fuel&
Filter&
Primer&
Bulb&
To&Engine&
Pulse&port&
To&Carburetors&
Equalizer&Line&
&Bulb&
Bypass&
North&Wing&582&S,LSA&Fuel&System&
,&
+&
s&
15&gal&Fuel&
Tank&