Small engines, such as those used in Troy Bilt pressure washers, are vulnerable to contamination by stale gasoline. The ethanol in today's fuel also clogs up small carburetor parts more swiftly than non-ethanol gas used to. Although there are other possible causes, stale fuel is most frequently the culprit when a pressure washer that has been sitting a while refuses to start.
Troy Bilt Machinery
Troy Bilt is a marque of MTD Products, which manufactures mass-market outdoor power equipment under several brand names, including Craftsman, Farm King, Ryobi and Yard-Man. The Troy Bilt line is sold primarily through the Lowes chain of home improvement warehouses.
Precursor Checks Before Disassembling Fuel Line
If there is an "on/off" switch, make sure it is switched to "on." Ensure that no wires have become dislodged during storage. Ensure that there is still fuel in the fuel tank. Replace the spark plug, oil filter -- if fitted -- and air filter. Check that there is a spark at the plug; relatively cheap spark plug testers are available from auto parts stores that fit over the plug end and dagnose the spark strength when you pull the starter rope. Check the oil level; many Troy Bilt motors have a safety device built into them that prevents the engine from firing if the oil level is low.
If the engine starts and briefly runs when you spray starting fluid directly in the carburetor's air intake, this suggests fuel is not reaching the carburetor and that all other systems are functioning. In Troy Bilt pressure washers, fuel is gravity fed from the tank to the engine, so the first test is simply to remove the fuel line from the inlet nipple of the carburetor; if fuel does not run out freely there is a blockage. Ensure the in-line fuel petcock is in the on position. If it is, remove the fuel line from the bottom of the tank; if fuel pours out, you must replace the fuel line. Black rubber fuel lines can collapse internally when the carburetor creates a vacuum after a long periods of disuse. Always exercise caution when working with gasoline: wear protective gloves and eyewear. Catch waste gas and disposed of it properly.
Gasoline ages and becomes stale in as little as two weeks. Small engines are far more susceptible to this phenomenon than are full-size automobile engines; their carburetors become varnished inside, and the varnish buildup clogs the tiny jets and feed lines. A small engine supplied with stale fuel will do nothing when the starter rope is pulled; it will not cough and splutter and "try" to start. Coughing and spluttering is indicative of air starvation and suggests a new air filter may be required.
If the pressure washer has been unused for longer than two weeks, drain the tank, the fuel line and the carburetor bowl, flush them, then refill the system with fresh gasoline and try starting the engine again. Typically, the float bowl is held in place by one bolt at its base. If the existing gasoline has somehow become contaminated with water, this process will resolve that issue, too. It may also be necessary to spray proprietary carburetor cleaner, available from most auto parts stores, into the carburetor while it is disassembled to remove varnish from the inner workings.
Pressure washers, and other machines that are only used periodically, are prime candidates for fuel stabilizers. Treat the fuel you use for these machines, and it won't turn bad as quickly. Some stabilizers also negate the deletorious effect that ethanol has on small engines.
Remove the float bowl from the bottom of the carburetor. If good fuel is in the float bowl, the bowl is clean and the float valve is moving freely, the issue is internal to the carburetor. You can buy carburetor service kits from the manufacturer and from its resellers; they are supplied with comprehensive instructions. That said, the kits are relatively expensive to the end user, and it is often cost-effective to have a small engine specialist perform the service.