If your pulse-jet engine will not start when following the normal starting procedures, there are some basic things that need to first be checked before tampering with the carburetor. Normally the carburetor is not at fault!

If the engine will not start or only makes a "Rumbling or Popping sound" when attempting to start, make sure that the following conditions have been met:

• Spark is present when the ignition switch is pressed (even when the Air Pump is operating).
• Air Pump is delivering Air to antechamber.
• 12 Volt DC supply is checking at least 8 volts.
• Machine has fresh gasoline of at least 87 Octane
• The air intake filter is clean and free of debris
• The splash guard screen beneath the filter cover is clean and open
• The "Throat Plate" inside the carburetor is fully open when the On/OFF Knob is in the ON position.
• The Primer Bulb draws gasoline from the tank and gas is visible in bulb.
• The carburetor adjustment screw is set at 1/2-5/8 of a turn open.
• There is no carbon formation in the engine neck or exhaust tube.
• The "Pulse-Pump" tube is connected from the antechamber to the Fuel Pump Side of the Carburetor.
• The gasoline tank is vented properly
• The gasoline filter is clean
• The gasoline line has a good sealed connection on each end and at the filter.

If your machine will still not start after trying these troubleshooting check points, your carburetor may be at fault.

Why is the carburetor prone to encountering problems?

Even though carburetors are much more reliable than other types of fuel/air metering systems, they require some preventative maintenance to ensure reliable operation. Things like using fresh gasoline and draining the gasoline tank before extended periods of storage will greatly benefit carburetor performance and reliability. What happens is that over time gasoline produces a varnish that coats all of the parts in the fuel system including the carburetor. This causes the inlet needle inside the carburetor to "stick" to its sealing surface and prevent gasoline from entering. A symptom of this condition is when attempting to start the engine, the engine will only make a "popping" sound, or will produce one large "POP" and then will not start. If this happens the fuel inlet needle may be stuck on its sealing surface. Another symptom of a stuck needle is if gasoline in the line coming from the gasoline tank does not move toward the carburetor when the engine tries to start.

How do I fix this problem?

To free the Inlet Needle you need to remove the Metering Chamber Cover (the side of the carburetor that is held on with 4 screws). Once removed, carefully remove the diaphragm and gasket beneath the plate paying close attention to their orientation. After removing the gasket and diaphragm you will be able to see the metering needle and a stainless steel lever that has a spring beneath it. It should not be necessary to remove the screw that holds the lever, spring and needle in position. However, if you notice a lot of tarnish and/or rust deposits inside the Metering Chamber, you should remove the plate on the opposite side of the carburetor (Fuel Pump Side) and clean the stainless steel inlet screen. Spray a carburetor cleaning solution onto the lever and around the needle. Slowly depress the lever to make the needle move freely within its bore. Re-assemble the carburetor and set the Metering Screw to ½-5/8 of a turn open. Retry starting the engine.

It is highly recommended that anytime a carburetor is disassembled for cleaning, the gaskets, diaphragms, spring, inlet needle and lever should be inspected and replaced if necessary.

Carburetor Kit P/N's:
Golden Eagle, Superhawk, Trailblazer, Patriot, Blackhawk, Mister III, Silver Cloud:
P/N-58237 Kit, Carburetor Gasket
P/N-58238 Kit, Gasket/Diaphragm

Mistermax
P/N-22101 Kit, Carburetor Gasket
P/N-22102 Kit, Gasket/Diaphragm
P/N-22104 Kit, Carburetor Repair