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21 Posts
Discussion Starter #1
OK my second big question of the day...

I have been looking at getting a more powerful inverter generator. Honda or Yamaha would be ideal, but they are very expensive and don't have something in the 3600W range. I wanted something to max out a 30-amp 125V outlet for home backup of single phase 120V circuits.

One thing I noticed is how much more WEIGHT the Yamaha and Honda generators have compared to their Chinese brethern. Obviously the Chinese generators and engines aren't as good as the Japanese, but what, specifically, accounts for the massive weight difference? What did they skimp on?

Here are some stats:

Honda EU3000iS...3000W....196cc....131 lbs.
Yamaha EF3000IS..3000W....171cc....136 lbs.

WEN 56310i-RV....3100W....212cc....81.4 lbs.
Champion 100233..3400W....192cc....80.9 lbs.
Predator 3500....3500W....212cc....99.2 lbs.
Westinghouse iGen4500.. ..224cc....98 lbs.
Generac IQ3500...3500W....212cc....109 lbs.
Briggs P4500.....4500W....224cc....115 lbs.

You'll notice that even when I throw in some more powerful generators, they STILL clock in at less weight than a Honda or Yamaha. Even the American B&S & Generac weigh a lot less.

So what accounts for that difference? Insulation? Copper vs aluminum? Cast iron?


165 Posts
Very interesting question and not much information out there on this.

Without tearing one or the other completely down, lets look at what can make that weight difference.

The heaviest components on an Inverter generator are the alternator assembly itself and the motor.
Let's give Honda and Yamaha the benefit of the doubt and assume they use they best materials available. Heavier wire for windings. More windings.... Heavier stronger Alternator casing.
Let's say the alternator on one of these weighs 10lbs more than cheaper priced comparable Inverter generators because of this.

Next is the motor. The single heaviest piece probably being the crankshaft, followed by the crankcase and then the cylinder and head assembly.
The crankshaft on these might be forged vs cast. That could account for another 5 - 10 lbs.(although i doubt any of these use a forged crankshaft).

The case could be a lighter weight casting compared to a heavier Honda / Yamaha casting. another 5 lbs maybe.
Pistons are usually cast aluminum, but cylinders can be steel (heavier) vs aluminum / steel sleeved. Rocker assemblies can be aluminum or steel.
It all adds up.

Next is the frame and plastics.
Maybe we can assume Honda and Yamaha put a bit more into each of these for quality and longevity sake accounting for another 5 lbs or so?

Another consideration "could" be that the Honda and Yamaha designs have been around longer and more recent generators have an advantage in design and lightweight materials for things such as the frame.

I don't know the exact answer and these are just some ideas. I "suspect" a good amount of this difference has to do with the weight of the power producing part of the generator itself.
These are just some thoughts since there are no other answers (yet).

Still, this is a good question and someone with more knowledge of the alternators themselves can provide more insight. I'll be watching this thread for replies.
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