Yamaha EF2400iS Generator Oil Change


In 2004, two back to back hurricanes decimated our area.  No power for 18 days.  I was fortunate enough to have a motorhome at the time, and promptly evacuated.  I've since sold it, and bought a house.  I later bought a travel trailer, which is always ready to roll in case another storm approaches.  If we are camping in the boonies, the generator gets a workout.

One of the interesting news stories that came out after those storms was a large number of generators died.  Conventional air cooled generators run at a constant fixed speed to make 60Hz power.  They run hotter due to the higher RPM, and the oil needs to be changed every 25 hours.  That's once a day for those running them non-stop.  People ignored the manufacturer's guidelines, and in 2 weeks, their generators seized up. Expensive lesson.

Inverter type generators, like this Yamaha, vary the speed based on the load.  The 60Hz waveform is made electronically, not mechanically, allowing it to run up to 1/4 load at idle.  After initial break-in, the recommended oil change interval is 100 hours.  I added a tach/hour meter, so this is easy to track.

One difficulty is the drain plug is underneath.  I have used the hoist in my garage to lift the generator by the handles, but it's a bit of a pain.  I ended up building a generator cart, details here, that took into account access to the drain plug.  No need to jack the generator, and the oil pan simply slides underneath.

0.63 quarts of 10W-30 is recommended.  Once the oil was changed, I put a sticker, with the date and the current hours from the meter, onto the body of the generator.  Won't have to guess when it needs to be changed again.

This is an easy task, don't neglect your generator or it will die when you need it most!


The 10" tall tires on the cart give plenty of room for the oil pan to slide underneath.

The drain plug is concealed by an oval plug.  It simply pops out.

The drain plug is a little recessed, but I didn't need an extension on the ratchet.

12mm.  This drain plug has a LONG bolt.

Drains straight down, and doesn't spew oil in every direction.  Automobile manufacturers could learn a lot here!

Once it was empty, I added a little fresh oil before re-installing the drain plug to flush any remaining contaminants.

These measured quart oil funnels are perfect for this task.  There's a valve on the bottom that prevents oil from flowing until you're ready.  I poured in the right amount, put the hose in the fill port, opened the valve, done.  Verified it was full with the dip stick. 

Ran the generator for about 1/2 hour with a 1500 watt heat gun plugged in.  It's running great, despite being 10 years old.  Put it away and cleaned up my mess.  Very easy to change the oil with the generator sitting on the cart.





Last updated 06/12/16    All rights reserved.