12 Steps to Guarantee Easy Startup for Your Marine Generator

Your marine generator is one of the most expensive and most sensitive pieces of boat equipment on board. Proper maintenance is critical for ensuring a long life and excellent performance for your marine generator. Whether your generator uses gasoline or diesel fuel or the generator brand is Kohler, Westerbeke, or Onan, some startup maintenance steps are universal. Following these guidelines will help you maximize your generator’s ability to do its job.

Your Marine Generator Pre-Startup Checklist

Is your marine generator running poorly? Check these 12 critical components prior to startup to ensure your generator is running at peak performance.

1. [caption id="attachment_399" align="alignright" width="150"] A raw water strainer with a clear bowl can be quickly inspected for debris or dirt.[/caption]

   Raw water strainer – You can inspect the raw water strainer through the glass to make sure the water inside is clean and clear. Check for any debris that you may need to clear too. If you need to open the strainer to clean it out, close your seacock first. Then, open the cover of the strainer, remove the basket and clean off any debris. After you return the basket, make sure you seat the o-ring cover properly so that it is sealed tightly. You can then open the seacock. When you start the generator, make sure to check the strainer for any leaks, especially around the cover and the inlet and outlet hoses.

2. Seacock – Speaking of the seacock, make sure it is open prior to starting the generator! You need water passing through the generator for it to cool properly. Don’t forget to open up the water supply. If the generator does not start after several attempts, close the seacock. Excessive starter motor cranking will continue to pump cooling water through the generator and into the exhaust system causing it to fill completely. This water can then run back into the generator engine and cause damage, It's best to close the seacock and correct the starting issue before reopening the water supply.
3. Raw water system – Check the exhaust overboard discharge for cooling water when you start the generator. If there is no discharge or if volume seems less than normal, you should inspect the raw water pump impeller. It’s a good practice to replace the impeller on at least an annual basis. Be sure to check the raw water pump weep holes for any sign of leaks. A leak would indicate a bad seal and/or shaft wear.
4. Coolant level – For closed-cooled or fresh-water-cooled generators, do a quick check of the coolant recovery tank to confirm there is coolant present in the cooling system. If the tank is empty, you will want to check the system level by removing the pressure cap. If the coolant is low or empty in the manifold – or if coolant appears to be contaminated – then you probably need to perform a cooling system flush. Refer to your generator’s operator manual for proper procedure on refilling the coolant. Usually, you should only need to flush your coolant system every 500 hours or so.
5. Oil level – Marine engines and generators should have their oil level checked before each use. You can do this easily using the dipstick (similar to how you check the oil level on your automobile). If the oil appears dark or dirty, you should probably change it. Watered down or milky looking oil could indicate more serious problems. Refer to your generator’s operator manual for specific oil recommendations; never use synthetic oil during the initial break-in period, and only use as directed by the generator manufacturer. Inspect the oil filter at this time. You usually only need to replace it every 100 operating hours or so.

[caption id="" align="alignright" width="150"] Keeping clean filters in your generator is an easy way to prolong their life and ensure the best operation possible.[/caption]

1. Fuel/water separator – Check the fuel/water separator filter for dirt and debris and to ensure the fuel has not broken down due to ethanol or is contaminated with water. For gasoline engines, always use a fresh unleaded fuel with an octane rating of at least 89 or higher, and no more than 10% ethanol content (no ethanol is best). For diesel engines, always use a quality brand of fuel with a No. 2 rating of 45 cetane or higher. If the filter is excessively dirty, change it at this time. If the generator experiences limited use, it may be best to add a fuel conditioner to every fill-up. This will help to maintain the integrity of the fuel system whether it is gasoline or diesel.
2. Belts – Check all of the engine belts for proper tension, and inspect for wear and tear. Check for belt dust on the front of the motor; if you find dust, you may need to tighten or replace some belts. Excessive belt dust may indicate a pulley alignment issue or wear in a rotating component such as a water pump, governor or alternator shaft. Rotate these components by hand; they should spin freely and have no side play. The drive belts for the raw water pump and alternator will only need to be changed as needed. You should change the engine timing belt usually every 1000 hours or every five years, whichever comes first.

3. [caption id="" align="alignright" width="150"] Run the bilge blowers to ensure no fumes are present prior to starting your genset.[/caption]

   Blowers – Before starting the generator, turn on the bilge blowers and let them run for a couple of minutes. Inspect the bilge for any fumes or fuel prior to starting the generator. If either is present, do not start the generator, and consult a qualified technician.

4. Air filter – Check the air filter for deterioration. Air filters have a tendency to dry out and break apart over time. The debris can then get sucked through the engine. (This is especially common on Kohler generators using Yanmar engine blocks.)
5. Battery connections – Closely inspect your battery posts and connections for signs of corrosion, and clean them accordingly. This is especially important on the first start after a long period of sitting. Check the state of charge of the battery. When a generator sit for an extended period of time corrosion can build up because the batteries continuously discharge. This is why we recommend you disconnect them.
6. Visually inspect engine – Take a few moments to look over the engine for any fuel, oil or water leaks. Check that all clamps and connections are tight. Inspect wiring and electrical connections to ensure they are clean and properly secure. Look for loose bolts and other hardware, and correct as needed.
7. Control panel – First, check your control panel and make sure all AC loads powered by the generator are turned off before starting the generator. Then, you can start the generator and turn on the main circuit breaker. Then, you may begin turning on various AC loads. Throughout the startup process, watch the engine gauges and AC voltage display to ensure that they display proper readings. If any gauges display a reading which is not consistent with normal operation, then shut down the generator and consult your operator manual and/or a qualified technician. When shutting down the generator, make sure to turn off all AC loads first, then turn off the main circuit breaker. Finally turn off the generator itself.

Don’t Forget Regular Marine Generator Maintenance Too

In addition to these daily maintenance tips, be sure to keep up with the regular maintenance cycle of your generator. Replacing spark plugs, anodes, water pump impellers, filters and more will help to guarantee a generator that provides you with maximum performance and enjoyable boating for many years to come.

If you have questions regarding the maintenance or repair of your boat’s generator, give our experts at Marine Parts Source a call at 866-388-0390. We can help answer your questions and get you the marine generator parts you need.