Using the MSR Whisperlite Backpacking Stove
Understanding how a MSR Whisperlite stove works is essential to reducing flareups and effectively priming the stove prior to lighting. The most important part of the process is how the fuel, white gas, changes from liquid in the bottle to a gas that burns with an intense flame. New users are often intimidated by the MSR Whisperlite, but if taught properly, there should be no problem lighting the stove.
Pressurizing the Fuel Bottle
White gas is stored as a liquid and put under pressure in the fuel bottle. The pressure, created by the fuel pump, forces the liquid white gas through the metal tube into the stove. Pumping the fuel bottle until resistence is felt will result in adequate pressure. The number of pumps will depend upon the amount of fuel in the bottle.
Heat Feedback
If you look closely at the path of the white gas, you will notice a loop that takes the liquid fuel above the flame
when the stove is operating. This is an essential stage called heat feedback. Heet feedback means that when the stove is burning, the flame heats the white gas up to the point that it turns from liquid to gas, much like water changes to steam at water's boiling point. Here is a diagram of that change from liquid to gas.
This process occurs when the stove is already started and burning. But how do I get to that point, where the gas is hot enough that it changes from liquid to gas?
Priming the MSR Whisperlite Stove
This is where the primer cup comes into play. If the white gas is still in liquid form when it makes it through the fuel line, it will collect in the primer cup. The liquid white gas in the primer cup then should be lighted with the fuel valve on the bottle closed. Lighting this heats up the very end of the fuel line and some of the remaing fuel in the line, creating enough heat to change the liquid to gas. This heated gas rises up through the stove and starts making a slight hissing sound. You may have to experiment with how much fuel is allowed into the primer cup to do this.
Lighting the MSR Whisperlite Stove
The next step, lighting the stove, is often made much more difficult than is necessary. The easiest method is to simply wait for all the fuel in the primer cup to burn up, turn the fuel valve back on, and light the stove at the top, much like lighting any gas grill. The stove may burn with an intense blue flame right away, but sometimes the heat feedback, mentioned earlier, needs a little longer to be completely effective. The more difficult method is to turn on the fuel while there is still liquid white gas in the primer cup, but enough heat to for the hissing sound to be started. It is a matter of timing.
Advanced MSR Whisperlite Techniques
Simmering can be achieved by reducing the pressure in the fuel bottle after the stove has been started and heated up. Turn the fuel off, let the flames burn out, and twist off the fuel pump until pressure is relieved. Afterwards, simply pump the bottle fewer times than you normally would and light the stove again.
MSR Whisperlite Maintenance
The most effective and common maintenance for the MSR Whisperlite is to simply shake. At the very end of the fuel line is the shaker jet, a tiny needle that is free to move up and down. By shaking the stove, carbon buildup is removed. The shaker jet should make a slight rattling sound.
The second most effective and common maintenance for the MSR Whisperlite is cleaning the fuel line. Cleaning the fuel line consists of pulling out and pushing in the cable that is within the fuel line. This removes the carbon buildup that limits the flow of fuel. You can use different tools for this, but the one that comes with the stove
works well. If this is done regularly, it is a simple task and the cable will freely move. If not, it may take considerable effort to get it all the way back in, repeating the in and out until all carbon has been removed. Be careful not to damage the cable.
Safety Considerations
1. Watch for leaks from the fuel pump and check o-rings.
2. Do not step, lean, or reach over the stove.
3. If there is too much fuel in the primer cup, leave the stove and let some evaporate prior to lighting.
4. Always handle boiling water carfully.
5. Do not use water to put out white gas fires, smother the fire with whatever is available; dirt, aluminum wind screen, pot/pan, etc..
6. Keep food and fuel separate. Some fuel will remain in the fuel line after the stove is out and needs to be drained appropriately.
What Next?
If you have mastered the workings of the MSR Whisperlite stove, I suggest you try making a pop can alcohol stove that weighs about one ounce!
Pressurizing the Fuel Bottle
White gas is stored as a liquid and put under pressure in the fuel bottle. The pressure, created by the fuel pump, forces the liquid white gas through the metal tube into the stove. Pumping the fuel bottle until resistence is felt will result in adequate pressure. The number of pumps will depend upon the amount of fuel in the bottle.
Heat Feedback
If you look closely at the path of the white gas, you will notice a loop that takes the liquid fuel above the flame
when the stove is operating. This is an essential stage called heat feedback. Heet feedback means that when the stove is burning, the flame heats the white gas up to the point that it turns from liquid to gas, much like water changes to steam at water's boiling point. Here is a diagram of that change from liquid to gas.
This process occurs when the stove is already started and burning. But how do I get to that point, where the gas is hot enough that it changes from liquid to gas?
Priming the MSR Whisperlite Stove
This is where the primer cup comes into play. If the white gas is still in liquid form when it makes it through the fuel line, it will collect in the primer cup. The liquid white gas in the primer cup then should be lighted with the fuel valve on the bottle closed. Lighting this heats up the very end of the fuel line and some of the remaing fuel in the line, creating enough heat to change the liquid to gas. This heated gas rises up through the stove and starts making a slight hissing sound. You may have to experiment with how much fuel is allowed into the primer cup to do this.
Lighting the MSR Whisperlite Stove
The next step, lighting the stove, is often made much more difficult than is necessary. The easiest method is to simply wait for all the fuel in the primer cup to burn up, turn the fuel valve back on, and light the stove at the top, much like lighting any gas grill. The stove may burn with an intense blue flame right away, but sometimes the heat feedback, mentioned earlier, needs a little longer to be completely effective. The more difficult method is to turn on the fuel while there is still liquid white gas in the primer cup, but enough heat to for the hissing sound to be started. It is a matter of timing.
Advanced MSR Whisperlite Techniques
Simmering can be achieved by reducing the pressure in the fuel bottle after the stove has been started and heated up. Turn the fuel off, let the flames burn out, and twist off the fuel pump until pressure is relieved. Afterwards, simply pump the bottle fewer times than you normally would and light the stove again.
MSR Whisperlite Maintenance
The most effective and common maintenance for the MSR Whisperlite is to simply shake. At the very end of the fuel line is the shaker jet, a tiny needle that is free to move up and down. By shaking the stove, carbon buildup is removed. The shaker jet should make a slight rattling sound.
The second most effective and common maintenance for the MSR Whisperlite is cleaning the fuel line. Cleaning the fuel line consists of pulling out and pushing in the cable that is within the fuel line. This removes the carbon buildup that limits the flow of fuel. You can use different tools for this, but the one that comes with the stove
works well. If this is done regularly, it is a simple task and the cable will freely move. If not, it may take considerable effort to get it all the way back in, repeating the in and out until all carbon has been removed. Be careful not to damage the cable.
Safety Considerations
1. Watch for leaks from the fuel pump and check o-rings.
2. Do not step, lean, or reach over the stove.
3. If there is too much fuel in the primer cup, leave the stove and let some evaporate prior to lighting.
4. Always handle boiling water carfully.
5. Do not use water to put out white gas fires, smother the fire with whatever is available; dirt, aluminum wind screen, pot/pan, etc..
6. Keep food and fuel separate. Some fuel will remain in the fuel line after the stove is out and needs to be drained appropriately.
What Next?
If you have mastered the workings of the MSR Whisperlite stove, I suggest you try making a pop can alcohol stove that weighs about one ounce!