The 30-second answer: Predator generators are reliable but they hate sitting with fuel in them. If yours won’t start after storage, drain the old gas, clean the carburetor bowl and jet, and make sure the fuel valve is fully open. Also confirm the oil is topped off — the low-oil sensor will block starting if the level is low. These three cover the large majority of Predator no-starts.
Harbor Freight’s Predator generators are a lot of machine for the money, and mechanically they are conventional small engines — which means they fail and get fixed the same way every other portable generator does. The difference is that the people who own them often store them for months between uses, and that is exactly what causes the most common no-start. Here is what I check on a Predator that will not fire.
Stale fuel and a gummed carburetor (by far the most common)
This is the number-one Predator complaint. The carburetor on these has small passages that varnish over after a few months with ethanol fuel. If your Predator ran fine last fall and will not start this spring, do not overthink it: drain the old fuel, pull the carb bowl, and clean the main jet and bowl with carburetor cleaner. If it fires for a second on starting fluid or fresh gas down the plug hole and then dies, that confirms a fuel-delivery problem at the carb. Our carburetor cleaning guide walks through it.
Fuel valve and fuel flow
Make sure the fuel valve is turned fully on — Predators have a clear position for it — and that the tank actually has fresh gas. Check the inline filter and that fuel reaches the carb. A surprising number of “won’t start” Predators just had the valve off or old gas in the tank.
The low-oil shutdown sensor
Predators, like most modern generators, have a low-oil sensor that prevents the engine from starting if the oil is low — it is protecting the engine. Check the oil on a level surface and top it to the full mark with the correct weight (typically a small-engine 10W-30). If the unit is sitting at an angle, the sensor can read low even with enough oil; level it and try again. If the sensor itself has failed, it can block starting with full oil — see our guide on the low-oil shutoff tripping with oil full.
Spark and the basics
If fuel and oil check out, pull the spark plug and confirm a strong blue spark and a clean, properly gapped tip. A fouled plug from previous flooding is common after repeated start attempts. Also confirm the engine switch and any choke lever are in the right positions — cold start means choke closed.
Keep your Predator starting easily
The single best thing you can do for a Predator is manage the fuel. Run it dry before long storage, or add a fuel stabilizer like Sta-Bil to every tank, and exercise the generator for a few minutes every month or two. Do that and the gummed-carb no-start — the thing that brings most of these in — simply stops happening. GeneratorFixIt is independent and not affiliated with Harbor Freight or Predator.