Lift Pump Vacuum Test; Lift Pump Diaphragm Test - BRP E250DHLSCS Service Manual

Results:
Normal pressure
Perform the Lift Pump Vacuum Test on
•
p. 173. Make sure no air leaks or restrictions
exist in the fuel supply hose or boat fuel system.
Low pressure
Check pulse hoses and fittings for restrictions.
•
Perform the Lift Pump Vacuum Test on
•
p. 173. Make sure no air leaks or restrictions
exist in the fuel supply hose or boat fuel system.
Check fuel flow through fuel lift pump. Use fuel
•
primer bulb to force fuel through pump.
No pressure
Check pulse hoses and fittings restrictions.
•
Check fuel flow through fuel lift pump. Use fuel
•
primer or primer bulb to force fuel through
pump.
Momentarily prime or squeeze primer bulb to
•
check gauge operation.
Check pulse hose and fittings for restrictions.
•

Lift Pump Vacuum Test

Confirm fuel supply to the fuel lift pump.
Temporarily install a vacuum gauge, T-fitting, and
8 in. (20.3 cm) of clear vinyl hose between the fuel
supply hose and fuel lift pump (inlet). Secure con-
nections with tie straps to prevent fuel or air leaks.
Do not use fuel primer bulb, man-
IMPORTANT:
ual fuel primer, or electric fuel pump primer to
restart outboard. A positive pressure in the fuel
supply could damage some vacuum gauges.
START outboard and run at FULL THROTTLE for
at least two minutes. Monitor clear vinyl hose for
the presence of air. Air bubbles indicate a faulty
hose, connection, or fuel tank pick-up. Repair, if
necessary, before proceeding.
There should be no air or vapor bubbles visible in
the clear hose. The maximum inlet fuel vacuum
should not exceed 4 in. Hg. (13.5 kPa) at the inlet
to the fuel lift pump under any operating condi-
tions (IDLE to WOT).
A higher vacuum indicates an excessive restric-
tion in the fuel supply. Repair as needed. Refer to
Fuel System Requirements on p. 33 for fuel sup-
ply component requirements.

Lift Pump Diaphragm Test

Perform this test only if a damaged pump is sus-
pected. This test does not check the performance
of internal fuel pump check valves.
Remove both pulse hoses from the crankcase fit-
tings.
Apply 15 psi (103 kPa) to each of the pulse hoses
of the pump. Replace lift pump if either side of
pump fails to hold pressure.
1. Pulse fitting
000243
FUEL SYSTEM
FUEL SYSTEM TESTS
1
000670
173
8