PUMP MAINTENANCE
See Illustration 11
to identify pump parts.
WARNING!
Always check for leaking fuel, especially after any stove or pump maintenance and
replacement of seals. Check for leaks near every seal, including the Pump Seal, Fuel Line connection,
Control Valve area, and Pump Plunger. If leaking fuel is found, Do Not Use Stove. Repair it or send it
to your MSR retailer or MSR Product Service Center for repairs.
INSPECTING AND REPLACING SEALS
Fuel Tube O-ring
1.
Remove Plunger.
See Lubricating the Pump Cup.
2.
Using the Jet and Cable Tool, rotate the Fuel Tube Bushing (
E
) counterclockwise and remove.
3.
Remove the Fuel Tube O-ring (
F
)
using the end of the fuel line or a safety pin.
4.
Inspect and replace if worn or damaged. (spare Fuel Tube O-ring included with your stove).
Control Valve O-ring
1.
Using the Jet and Cable Tool, loosen the Stop Nut (
B
).
2.
Unscrew and remove the Control Valve (
C
).
3.
Inspect and replace O-ring if worn or damaged.
Pump Seal
1.
The Pump Seal (
J
)
surrounds the pump body.
2.
Remove the Pump Seal with your thumbs.
3.
Replace Pump Seal if worn or damaged. Ensure that top edge of Pump Seal seats securely over
rim on pump body.
See Illustration 10.
Replacement O-rings and Pump Seals
can be found in the Annual Maintenance Kit (for all stoves)
or the more comprehensive Expedition Service Kits (for each individual stove) purchased separately
from your local MSR Dealer.
LUBRICATING THE PUMP CUP
Note: Instructions showing 1, 2, and 3 arrows and “OPEN HERE” position are printed on the Plunger Shaft.
1.
Push Plunger (
G
)
in halfway so that Arrow 1 is lined up with the Plunger Bushing (
H
).
2.
Twist the Plunger counterclockwise (Arrow 2) until you hear it click free.
3.
Pull out the Plunger (Arrow 3).
4.
Rub MSR Pump Cup Oil (or other mineral-based oil or saliva) onto the Pump Cup (
I
).
5.
To re-insert: Hold the Plunger Shaft and align the top of the Plunger Bushing with Arrow 1 on the
Plunger Shaft.
6.
Align the Plunger Bushing Legs with the Locking Holes (
D
) in the Pump Body.
7.
Push the Plunger and Plunger Bushing into the Pump Body until the Legs snap into the locking holes.
TROUBLESHOOTING
Problem:
Leaking Fuel Cause: Solution:
Problem:
Poor Performance Cause: Solution:
For instruction on above, see STOVE MAINTENANCE and PUMP MAINTENANCE sections.
At Pump and Fuel Bottle
Connection
Damaged or Missing Pump Seal
Replace Pump Seal
At Pump and Fuel Line
Connection
Damaged or Missing Fuel Tube
O-ring
Replace Fuel Tube O-ring
At Control Valve Stem
Damaged or Missing Control
Valve O-ring
Replace Control Valve O-ring
In Pump Plunger Chamber
Obstructed Check Valve
Clean Check Valve Cavity
Erratic Yellow Flames
Improper Preheating
Repeat Preheating Stove
Slow Boil Times
Clogged Jet or Fuel Line
Clear Jet and Clean Fuel Line
Diminished Flames at Altitude
Insufficient Airflow
Open Windscreen Slightly
Dry Pump Cup
Lubricate Pump Cup
Plunger Hard to Pump
Low Fuel Bottle Pressure
Pump the Plunger
Diminished Flames
Pump Not Pressurizing Fuel Bottle
Lubricate Pump Cup
Dry Pump Cup
CLEANING THE CHECK VALVE
If the stove does not maintain pressure, the Check Valve may not be functioning properly.
1.
Turn the Check Valve (
K
)
counterclockwise and remove the Check Valve Assembly.
2.
Clean any debris from the seal and cavity.
3.
Re-insert the Check Valve Assembly.
