Why generators need more frequent service in Port St. Lucie
Onan and Cummins built their service intervals based on continental US averages - moderate humidity, mid-range temperatures, low salt-air exposure. Florida coastal conditions compress those intervals. The three biggest factors:
- Ethanol fuel + heat = carburetor gum. Modern 10% ethanol gas separates and gels in 30 days in Florida heat. A generator that sits unused for 60+ days will likely need carburetor service when it does come back out.
- Humidity attacks the fuel system. Water condenses inside the fuel tank, ends up in the carburetor bowl, corrodes jets and seats.
- Salt-air corrosion on alternator brushes and battery connections. Coaches stored near the coast (Hutchinson Island, Fort Pierce, Jensen Beach) develop terminal corrosion within 12 months.
Practical impact: the Onan 4000 'service every 150 hours' becomes 'service every 100 hours, plus full fuel system inspection every 6 months even if you didn't run it'.
The PSL Onan / Cummins maintenance schedule that actually works
This is the schedule we follow for PSL coaches:
| Interval | Service | Cost |
|---|---|---|
| Every 50 hours OR 3 months idle | Oil + filter, air filter inspect, run 30 min under load | $95-145 |
| Every 100 hours OR 6 months idle | All of above + fuel filter, spark plug check | $145-225 |
| Every 200 hours OR annually | All of above + carb clean, valve adjust (Onan QG/QD) | $285-425 |
| Every 500 hours | Full inspection: rings, governor, voltage regulator | $425-650 |
| After 5+ years stored uncovered | Full fuel system rebuild (likely) | $520-780 |
The key one most owners miss: 3-month idle service. If your coach sits unused for 3+ months, the generator gets 30 minutes of run time under load (run the AC) before you tow anywhere. That single habit prevents 60-70% of the carburetor problems we see.
Common Onan and Cummins failures in PSL
By model, here's what we see most often:
Onan KY / Microquiet 4000 (most common in PSL Class C coaches)
- Won't start - carburetor. Most common issue. Ethanol gum in the float bowl jets. Carb clean is $185-265.
- Starts but won't stay running. Usually the fuel solenoid stuck closed or low fuel pressure. $145-225.
- Runs but no AC output. Brushes worn or voltage regulator failed. $285-425.
- Hard start / smokes on startup. Worn rings, time for top-end inspection. $425-650.
Onan QG 5500 / QG 6000 (typical in Class A coaches)
- Surging / hunting. Governor adjustment or carburetor air leak. $185-325.
- Loss of power under load. Air filter blocked or fuel filter restricted. $145-225.
- Battery won't charge / generator runs but starting battery flat. Charging system fault, alternator or regulator. $285-485.
Cummins Onan QD 6000 / QD 8000 diesel
- Hard start in cold weather. Glow plugs or fuel system. $245-385.
- Black smoke under load. Air filter or fuel injection issue. $285-485.
- Runs but won't take load. Cooling system or controller fault. $325-525.
Storage prep for PSL hurricane / summer downtime
If you're storing your coach in Port St. Lucie from May through October (typical snowbird pattern):
- Run the generator under load for 30 minutes before storage. Run the AC during this time so the gen is doing real work, not just idling.
- Add fuel stabilizer (Sta-Bil 360 or Pri-G) to the tank. Run another 5-10 minutes after adding so stabilized fuel reaches the carburetor.
- Disconnect the generator starting battery if separate from house batteries. Prevents parasitic drain killing the battery during storage.
- Cover the exhaust opening with steel wool stuffed in the pipe. Keeps mud daubers (huge problem in PSL) from nesting inside the muffler.
- Schedule a wake-up service for September. We come out before snowbird season starts, run a fresh oil change, swap filters, verify load output, so you're ready to roll.