25 Hour Generator Maintenance

This section details generator maintenance intended as a twenty-five hour maintenance item that should be performed at or before every 25 hours of flight.

To achieve the longest life from any engine, preventative maintenance is necessary to ensure the mechanical and electrical systems that it is composed of operate as efficiently as possible or are otherwise replaced.

Air Filter Replacement

Air Filters prevent any contaminants or environmental fallout from getting into the combustion chamber that would otherwise cause a poor ignition cycle. As a result, over time these filters will lose their ability to properly intake air, and should be replaced every twenty-five hours of flight. To replace, simply pull the air filter off the intake, and place another in its place while ensuring the air temperature sensor is placed between the filter and intake during installation.

Fuel Filter Replacement

Begin by removing the fuel line grommet located at the top of the fuel tank, and pull the fuel filter through the internal baffles. Firmly grasp the filter with one hand, while grasping the attached fuel line close to the nipple of the filter, and pull the fuel line off. If the fuel line is difficult to remove, cut the fuel line as close to the filter as possible, and use a razor knife to carefully score and remove the remaining fuel line. Before installing a new fuel filter, make sure the nipple is clear of any previous fuel line or material, and that the fuel line to be mated with the fuel filter has been trimmed flush.

Fuel Line Replacement

Begin by removing the fuel line grommet located at the top of the fuel tank, and pull the fuel filter through the internal baffles. Remove each fuel line from its respective brass-L pipe for both the internal and external fuel lines. Remove the large clear and large yellow fuel line from the generator taking note of which nipple they mate to. If any fuel line is difficult to remove, cut the fuel line as close to the nipple as possible, and use a razor knife to carefully score and remove the remaining fuel line. Lay out each fuel line and measure the length of each segment. Prepare fresh fuel lines using these measurements making sure the end of each line is trimmed flush. Insert each new fuel line in place of the pre-existing fuel line.

Spark Plug Replacement

Begin by removing the spark plug boot, located at the bottom of the generator. Using the spark plug removal wrench, loosen the spark plug and remove by hand being careful not to break the spark plug upon exit. Replace the spark plug with a new NGK-CMR7H, inserting the spark plug into the ignition chamber and tightening until snug. Be careful not to overtighten the new spark plug as this may result in fracturing and poor spark while running.

Braided Wire Damper Replacement

Inspect each braided damper around the generator mounting clamps. If any braided steel damper exhibits signs of wear or fraying, replacement is required. To remove a damper, loosen both the top and bottom retaining screws with a 2.5mm hex allen wrench and remove the faulty damper. Replace with a new braided damper, and insert two new screws with blue loctite. Repeat this procedure for all damaged braided steel dampers.