* Clogged Fuel Jets or Passages: This is the most probable cause. Tiny passages in the carburetor can become blocked with debris, varnish, or even gummed-up fuel. The fuel pump might be delivering fuel, but it can't get *into* the engine. This requires a thorough carburetor cleaning or rebuild.
* Float Level Problems: The carburetor float controls the fuel level in the bowl. If the float is stuck, sunk, or misadjusted, the fuel bowl might not be filling properly, or it might be overflowing. This can lead to a lean condition (not enough fuel) or flooding (too much fuel).
* Vacuum Leak: A significant vacuum leak in the intake manifold or carburetor gasket can disrupt the carburetor's ability to draw fuel. The engine might run briefly with added fuel, but the vacuum leak prevents it from drawing fuel properly from the bowl.
* Bad Needle and Seat: The needle and seat are inside the carburetor and control the fuel flow from the bowl into the engine. If they are worn or damaged, they won't seal properly, leading to a lean condition or fuel leakage.
* Fuel Filter: Although you've checked the pump, a clogged fuel filter *before* the pump could still restrict fuel flow. Check this even if you've checked the pump, it's a low-hanging fruit.
What to do next:
1. Check the fuel filter: This is the easiest and quickest check. Replace it if it's dirty.
2. Remove and thoroughly clean or rebuild the carburetor: This is the most likely solution. You'll need a carburetor cleaning kit and possibly a rebuild kit, depending on the condition. There are many online resources and videos showing how to do this for a Suzuki Samurai carburetor (ensure you get the right one for your year and model). Pay close attention to the float level adjustment.
3. Inspect the intake manifold and carburetor gasket for leaks: Look for cracks or damage. Replace the gasket if necessary.
4. If you're not comfortable working on carburetors, take it to a mechanic: Carburetors are delicate and require specific knowledge to work on correctly.
Don't overlook the simple things, but the carburetor is the most likely suspect given the symptoms you've described. Remember to be meticulous and patient when working with a carburetor. A small mistake can create more problems.
