Frequently Asked Questions
Do you have a question about a Cummins Onan Marine generator? Browse through our Frequently Asked Questions below -- you may find that we already have an answer for you. We will be adding new questions regularly, so please check this page often.
If your question isn't addressed here, please contact your local Certified Dealer/Distributor of Cummins Onan Marine generators for assistance. They are your local source for Marine parts and accessories, manuals, technical advice, maintenance service and repairs. Or if you already own a Cummins Onan Maine generator you can download or view your operators manual online.
What generator checks or procedures should I follow before a vacation trip?
We recommend:
- At least one week prior to trip or guest arrival visit your boat, review your Cummins Onan Marine Operators Manual, and perform all necessary services (filters, zinc's, belts, etc). Should maintenance be required, depending on the season, local service centers may have a couple days wait for technician availability. When a certified Cummins Onan technician is necessary it is recommended to call around to all local Cummins Onan service centers to get the best-scheduled appointment.
- Be sure battery is fully charged
- Inspect and tighten all hose clamps and fittings; especially exhaust connections
- Check all fluid levels and add as necessary or replace fluid, if necessary, for expected operating temperatures
- Perform all pre-start checks as outlined in the Operator's Manual verify all through hull valves are open as necessary
- Start and run generator set inspecting for visual leaks and odd noises
- Make start and stop attempts from all stations
- Turn on all loads expected to be operated during trip, being sure not to overload generator. Run generator set for at least 30 minutes under load
- Note operational hours and add to expected hours to log on trip. Based on the total hours identify the necessary spare parts required for service based on service intervals outlined in Operator's Manual. Purchase the necessary spares or a cruise kit from your local Cummins Onan Dealer/Distributor
- Write down phone numbers of service centers located at or near trip destination in the event of unexpected part needs or service is required
What tips or procedures do you recommend for day to day operation of my Cummins Onan marine generator set?
Here are some good general tips. You'll find other helpful information in your Operator's Manual which can be viewed online or ordered through your local Cummins Onan Dealer/Distributor if you did not receive one with your generator set.
- Inspect and clear sea water strainers of debris, do not wait until they clog. Lack of inspection could result in seawater pump impeller damage.
- Inspect area around generator set to be sure nothing has moved or been knocked loose (rags, cleaning equipment, tools, spare parts, etc.) while underway, that could block air inlet or outlet or damage wires or hoses.
- Inspect generator set for fluid levels, leaks, and required service intervals based on operational hours and perform any identified maintenance as necessary.
I want to add a sound shield to my Cummins Onan Marine generator set. Can I do that after the fact?
Yes. Cummins Onan generators have a complete line of accessories including sound shields. Contact your Cummins Onan Distributor/Dealer who can quote you a price and provide the installation expertise you need.
How do I prepare my Cummins Onan generator set for extended storage?
We recommend:
- Read through your Cummins Onan Operator's Manual for familiarization as necessary.
- Start and run the generator set at all stations.
- Allow generator set to run applying all load available up to rated output.
- When possible simulate faults to test control operation.
- Disconnect and the store battery per manufacturer's guidelines - reference BCI (Battery Council International, Chicago IL).
- Drain the oil and replace with new, document viscosity.
- Verify coolant is capable of storage temperatures and adjust as necessary. If coolant is two years old or older drain and replace with mixture capable of storage temperatures. Maximum ratio of ethylene glycol to distilled water is 50/50, recommended is 40/60.
- Remove raw water impeller and store in cool dry place or discard as necessary.
- Drain and clean sea water side of heat exchanger. Remove any sea growth or debris if excessive scaling is noticed. A professional cleaning may be required by a local Cummins Onan service center.
- Drain water lift muffler.
- Wipe down, clean, and lightly oil any parts that could rust.
- Touch up any paint chips or scratches.
- Document all work performed including load and control tests. Make repairs or note any failures that need to be addressed before returning the unit to service.
When returning the generator set to service:
- Review document for storage and make repairs if necessary for any failures or issues noted.
- Be sure battery is fully charged.
- Inspect and tighten all hose clamps and fittings; especially exhaust connections.
- Check all fluid levels and add as necessary or replace fluid, if necessary, for expected operating temperatures.
- Check for presence and tightness of muffler drain plug or install plug if removed for storage.
- Check for presence and tightness of heat exchanger drain plug or install if removed for storage.
- Install removed sea water impeller or new impeller if dried out or otherwise damaged, or discarded at storage.
- Replace fuel filters primary and secondary.
- Clean or replace all rusted and corroded terminals and wire connections.
- Clean and inspect generator brushes and slip rings, if equipped.
- Connect fully charged battery.
- Perform all pre-start checks as outlined in the Cummins Onan Operator's Manual and verify all through hull valves are opened as necessary.
- Start and run generator set inspecting for visual leaks and odd noises.
- Make start and stop attempts from all stations.
- Check and adjust frequency as needed.
