{ "formatVersion": 1, "title": "RV Onboard Generator Service (by Engine Hours)", "description": "Scheduled service for an RV's onboard generator. The single most important idea here: a generator is serviced on ENGINE HOURS from its hour meter, never on the coach's odometer and never on the calendar. A genset that has idled through three summers of air conditioning may be far past due on a motorhome that has barely moved.", "category": "engine", "subcategory": "Onboard generator", "difficulty": "intermediate", "tags": ["rv", "generator", "engine hours", "maintenance", "carbon monoxide"], "language": "en", "estimatedMinutes": 175, "estimatedCost": 75.0, "currency": "USD", "author": { "name": "Trackara", "bio": "Official Trackara blueprint template", "url": "https://trackara.app/blueprints" }, "vehicleCompatibility": [ { "make": "Cummins Onan", "model": "RV onboard generator", "notes": "Written around a gasoline-fuelled onboard RV genset, the most common type. Diesel and LP units follow the same structure but substitute a fuel filter and injection service for the spark plug. Service intervals, oil capacity, plug gap and filter part numbers all come from YOUR generator's operator manual. This blueprint deliberately does not state them." }, { "make": "Generac", "model": "RV onboard generator", "notes": "Same procedure shape. Use the manufacturer's own hour intervals." } ], "requiredTools": [ "Socket set", "Wrench set", "Oil filter wrench", "Spark plug socket with rubber insert", "Spark plug gap gauge", "Torque wrench", "Low-profile oil drain pan", "Funnel with a flexible spout", "Flashlight", "Compressed air or a soft brush", "Nitrile gloves", "Shop rags" ], "parts": [ { "name": "Generator engine oil", "kind": "required", "quantity": 1, "estimatedCost": 20.0, "notes": "Viscosity and capacity come from the generator's own manual, not the coach's engine spec. Genset sumps are small, often under two quarts, so buy for that, and note that many manufacturers specify a different viscosity for cold-weather operation." }, { "name": "Generator oil filter", "kind": "required", "quantity": 1, "partNumber": null, "estimatedCost": 14.0, "notes": "Specific to your generator model. Look it up from the model and serial plate on the genset itself, not from the RV's make." }, { "name": "Generator air filter", "kind": "required", "quantity": 1, "partNumber": null, "estimatedCost": 18.0, "notes": "Usually on a longer hour interval than the oil. Inspect at every oil change and replace at the manufacturer's interval, or sooner if you camp on dirt." }, { "name": "Spark plug", "kind": "optional", "quantity": 1, "estimatedCost": 8.0, "notes": "Gasoline units only. Type and gap are in the operator manual and are engine-specific. Do not gap it to a car figure." }, { "name": "Fuel filter", "kind": "optional", "quantity": 1, "estimatedCost": 15.0, "notes": "Diesel units, and some gasoline units with an inline filter. Follow the manual's interval." }, { "name": "Oil drain plug washer", "kind": "optional", "quantity": 1, "estimatedCost": 1.5 }, { "name": "Shop rags", "kind": "consumable", "quantity": 1, "estimatedCost": 3.0 }, { "name": "Nitrile gloves", "kind": "consumable", "quantity": 1, "estimatedCost": 1.0 } ], "steps": [ { "stepNumber": 1, "title": "Read the hour meter and write the number down first", "description": "Find the generator's hour meter, usually on the genset control panel, on the remote start panel inside the coach, or displayed by holding the stop switch on some units. Write the reading down before you do anything else. Every decision in this blueprint is made from that number.", "estimatedMinutes": 10, "tools": ["Flashlight"], "parts": [], "warnings": [], "tips": [ "If the hour meter is dead or has been replaced, say so in your log and start counting from today. An unknown hour count should be treated as 'service is due now'.", "Log the hours every time you run the generator for any length of time. That single habit is what makes this schedule work." ], "checklist": ["Hour meter located", "Current reading written down", "Reading logged against today's date"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 2, "title": "Get YOUR intervals from the operator manual", "description": "Open the generator's own operator manual and copy out its service schedule: the break-in oil change hours, the ongoing oil and filter interval, the air filter interval, the spark plug or fuel filter interval, and the valve adjustment interval. These are stated in engine hours. Write each one into this blueprint so you never have to look them up again.", "estimatedMinutes": 10, "tools": [], "parts": [], "warnings": [ "Do not substitute the coach's mileage-based schedule or a 'once a year' habit. A genset running the roof air all summer accumulates hours astonishingly fast while the odometer never moves." ], "tips": [ "The model and serial number are on a plate on the generator itself. Manufacturers publish the manuals free by model number.", "Note the break-in interval separately. New and rebuilt gensets get an early first oil change that never repeats." ], "checklist": [ "Oil and filter interval (hours) recorded", "Air filter interval (hours) recorded", "Spark plug or fuel filter interval (hours) recorded", "Valve adjustment interval (hours) recorded", "Oil capacity and viscosity recorded" ], "imageUrls": [], "videoUrl": null }, { "stepNumber": 3, "title": "Shut down and make the generator safe to work on", "description": "Stop the generator and let it cool. Turn off the fuel supply if there is a shutoff. Disconnect the generator's starting battery negative, or at minimum pull the spark plug lead and the start fuse, so nothing can crank while your hands are in the compartment. Turn off the AC breakers the genset feeds.", "estimatedMinutes": 10, "tools": ["Socket set", "Wrench set"], "parts": [], "warnings": [ "An onboard generator can be started remotely from inside the coach. Isolate it so that cannot happen while you are working.", "The exhaust and the engine stay hot long after shutdown. Give it time.", "The generator produces line-voltage AC. Treat its output wiring as live until proven otherwise." ], "tips": [ "If your genset is on a slide-out tray, pull it out. Working on it in place is how bolts get dropped into places you cannot reach." ], "checklist": ["Generator stopped and cool", "Start circuit isolated", "Fuel shutoff closed if fitted", "AC breakers off"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 4, "title": "Change the engine oil and filter", "description": "Warm oil drains better, so ideally do this shortly after a short run rather than stone cold. Position the low-profile pan, pull the drain plug or open the drain valve, and let it empty. Spin the old filter off, oil the new filter's gasket, and fit it per the instruction printed on the filter. Refit the drain plug with a fresh washer and refill with the exact capacity from the manual, then check the level on the dipstick.", "estimatedMinutes": 35, "tools": ["Socket set", "Oil filter wrench", "Low-profile oil drain pan", "Funnel with a flexible spout", "Nitrile gloves", "Shop rags"], "parts": [ { "name": "Generator engine oil", "kind": "required", "quantity": 1 }, { "name": "Generator oil filter", "kind": "required", "quantity": 1 }, { "name": "Oil drain plug washer", "kind": "optional", "quantity": 1 } ], "warnings": [ "Genset sumps are small. Overfilling one by half a quart is proportionally enormous and will push oil past the seals.", "Confirm the old filter gasket came off with the old filter." ], "tips": [ "Generator compartments have no room. A flexible-spout funnel and a length of hose on the drain make the difference between a 30-minute job and a two-hour one.", "Many gensets have an oil drain extension hose specifically so you can drain without removing the unit. Find out if yours does." ], "checklist": ["Old oil drained", "New filter fitted and gasket oiled", "Drain plug refitted with washer", "Refilled to the manual's capacity", "Dipstick reads correct"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 5, "title": "Inspect or replace the air filter", "description": "Open the air cleaner housing, take the element out, and look at it against a light. Replace it at the manual's hour interval, or immediately if it is oil-soaked, damaged, or so loaded that light will not pass. Wipe the housing out before fitting the new element and make sure the seal seats all the way round.", "estimatedMinutes": 10, "tools": ["Socket set", "Compressed air or a soft brush", "Shop rags"], "parts": [ { "name": "Generator air filter", "kind": "required", "quantity": 1 } ], "warnings": [ "Do not run the generator with the air cleaner removed. It is also the flame arrestor path on many units." ], "tips": [ "Dusty or dirt-lot camping halves the useful life of an air filter. Judge by the element, not only by the hour count.", "Never oil a dry paper element." ], "checklist": ["Element inspected", "Housing wiped clean", "New element seated and sealed all round"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 6, "title": "Spark plug (gasoline) or fuel filter (diesel)", "description": "On a gasoline unit at its plug interval: remove the plug with a proper plug socket, read its condition, and fit a new one gapped to the manual's figure and torqued to the manual's spec. On a diesel unit: replace the fuel filter and bleed the fuel system per the manual.", "estimatedMinutes": 20, "tools": ["Spark plug socket with rubber insert", "Spark plug gap gauge", "Torque wrench", "Wrench set"], "parts": [ { "name": "Spark plug", "kind": "optional", "quantity": 1 }, { "name": "Fuel filter", "kind": "optional", "quantity": 1 } ], "warnings": [ "Gap the plug to the figure in the GENERATOR manual. Small industrial engines do not use the same gap as a car engine, and a wrong gap causes hard starting and misfire.", "Torque the plug to spec. Small aluminium heads strip easily.", "Diesel: keep fuel off hot exhaust components and clean up spills before starting." ], "tips": [ "Read the old plug before you throw it away. Heavy black soot points to a rich mixture or a choked air filter; oily deposits point at something more serious.", "Blow the debris out of the plug well before you pull the plug, so nothing drops into the cylinder." ], "checklist": ["Old plug or filter removed and inspected", "New part gapped/primed per the manual", "Torqued to spec", "Diesel fuel system bled if applicable"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 7, "title": "Clean the spark arrestor and clear the compartment", "description": "Most RV generators have a spark arrestor screen in the exhaust that has to be cleaned periodically. It is a fire-safety device and many campgrounds and forestry areas legally require a functioning one. Remove the screen, clear the carbon, and refit it. While you are in there, clear leaves, nests and debris out of the whole generator compartment and check the cooling air inlet and outlet are unobstructed.", "estimatedMinutes": 20, "tools": ["Socket set", "Wrench set", "Compressed air or a soft brush", "Flashlight"], "parts": [], "warnings": [ "Rodent nests in a generator compartment are both a fire hazard and a wiring hazard. If you find one, wet it down with disinfectant rather than sweeping or blowing it dry, and wear gloves and a respirator.", "A blocked cooling air path will cook the generator. Do not skip this." ], "tips": [ "Carbon that will not brush off usually comes away after the screen has been heated with a torch on a non-flammable surface, then wire-brushed.", "Take a photo of the compartment when it is clean. It makes next year's inspection a five-second comparison." ], "checklist": ["Spark arrestor removed, cleaned, refitted", "Compartment cleared of debris and nests", "Cooling inlet and outlet clear"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 8, "title": "Inspect the entire exhaust system for leaks", "description": "Follow the exhaust from the engine to the tailpipe. Look for soot trails, rust holes, cracked or missing hangers, loose clamps, and a tailpipe that no longer extends clear of the coach's side or underbelly. Check that the exhaust outlet is not aimed at a window, a vent, or the area where people sit outside.", "estimatedMinutes": 20, "tools": ["Flashlight", "Socket set"], "parts": [], "warnings": [ "This is the step that matters most. Generator exhaust is carbon monoxide, it is colourless and odourless, and RV generator CO poisoning kills people every year. A leaking exhaust inside a coach is not a maintenance item to schedule. It means the generator does not run again until it is fixed.", "Never run the generator with the exhaust discharging under a coach that is skirted, parked against a wall, or backed up close to another vehicle.", "Never sleep with the generator running unless you have a working CO alarm." ], "tips": [ "Black soot streaking anywhere along the exhaust is a leak until proven otherwise.", "Check the exhaust while someone runs the generator, from OUTSIDE the coach, listening for a ticking or blowing sound that changes with load." ], "checklist": [ "Full exhaust run inspected", "No soot trails or rust perforation", "All hangers and clamps sound", "Tailpipe extends clear of the coach", "Outlet not directed at a window, vent or living area" ], "imageUrls": [], "videoUrl": null }, { "stepNumber": 9, "title": "Test the carbon monoxide alarm", "description": "Press the test button on the coach's CO alarm and confirm it sounds. Check the manufacture date printed on the unit. CO alarms have a finite service life and expire whether or not they have ever been triggered. Replace the battery, or the whole alarm if it is past its stated life.", "estimatedMinutes": 5, "tools": [], "parts": [], "warnings": [ "A CO alarm past its expiry date is decoration. Replace it.", "The test button confirms the sounder and the electronics, not the sensor's sensitivity. Age it out on schedule regardless." ], "tips": [ "Log the alarm's replacement date here so it comes up with the generator service instead of being forgotten." ], "checklist": ["Alarm sounds on test", "Manufacture/expiry date checked", "Battery replaced or alarm replaced"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 10, "title": "Reconnect, start, and run it under load", "description": "Reconnect the start circuit and fuel, start the generator, and let it warm up. Then put a real load on it for a sustained period: run the air conditioning, or the microwave and a heater together. Watch for smooth running under load, correct voltage and frequency if you have a meter, no surging, and no leaks at the filter or drain plug.", "estimatedMinutes": 25, "tools": ["Flashlight"], "parts": [], "warnings": [ "Run it outdoors, in the open, with the coach's windows on the exhaust side closed.", "Do not run it inside a garage, even with the door open." ], "tips": [ "Generators dislike long periods of no-load running far more than they dislike work. Loading it properly during the test is part of the maintenance, not just verification.", "A genset that surges or will not hold load under air conditioning usually has a fuel delivery or carburettor issue, not an electrical one." ], "checklist": ["Starts cleanly", "Runs smoothly under sustained load", "No oil leaks at filter or plug", "No unusual exhaust smell or smoke"], "imageUrls": [], "videoUrl": null }, { "stepNumber": 11, "title": "Record the hours and set the next service point", "description": "Write down the hour meter reading at completion, what you replaced, and the part numbers you actually used. Then calculate the next due point: this reading plus the interval from step 2. That hour number, not a date, is what the next service is scheduled against.", "estimatedMinutes": 5, "tools": [], "parts": [], "warnings": [], "tips": [ "Record part numbers as you fit them. Next time you can buy without opening the manual.", "Keep the old plug or filter until the next run is complete, in case something needs comparing." ], "checklist": [ "Hours at completion recorded", "Parts and part numbers recorded", "Next service due at (this reading + interval) written down" ], "imageUrls": [], "videoUrl": null }, { "stepNumber": 12, "title": "Set the between-service exercise habit", "description": "A generator that sits unused is far more likely to fail than one that runs. Manufacturers generally ask for a regular exercise run under load. Check your manual for the interval and duration it specifies, and put that on the calendar. Fuel stabiliser in the tank matters for the same reason if the coach is stored.", "estimatedMinutes": 5, "tools": [], "parts": [], "warnings": [ "Exercise runs still produce carbon monoxide. Same rules: outdoors, exhaust clear, CO alarm working." ], "tips": [ "The failure mode of a stored generator is almost always the fuel system gumming up, followed by a flat start battery. Regular loaded runs address both.", "Log each exercise run's hours here. It keeps the hour meter figure honest between services." ], "checklist": ["Exercise interval from the manual noted", "Recurring reminder set", "Fuel stabiliser plan decided for storage"], "imageUrls": [], "videoUrl": null } ], "coverImageUrl": null }