Only run for one hour break in so far but seems nice and is quiet. Only issue so far is when researching this before buying, the manual stated it was a floating neutral generator with an included bonding plug which is what I wanted for connection to my house as backup power. However, when it arrived it is a bonded neutral and there is no information on the Genmax FAQ page that the manual points you to on where the neutral to ground bond is that you need to remove. Genmax service also still thinks this model is neutral floating by default and I had to send them a picture of my front panel to show them that it said Neutral Bonded. They did not have any updated instructions for this model either.

This generator claims to have 6500 W running and 8500 W start but the generator I just replaced it with had 2900 running 3200 starting but was as powerful as this one. Also, the generator has shut itself off two nights in a row when I was sleeping.

I bought this unit after my Champion generator took a dump on me. Just wanted to say this unit has been nothing short of Amazing! It has the necessary outlets and not the typical over complicated amount, as well as extremely portable! Good Job Genmax!

Great generator used for over 200 hours, easy to use, overall quiet and provides a lot of power! Used on our food truck and at times ran for 72 hours straight with short breaks to refuel. Got it on a $750 samsclub discount great deal!

Purchased the Genmax 11000 about 8 weeks ago. The Genmax arrived via a delivery truck and everything was in perfect condition. The generator was well boxed to ensure the product was not damaged. I was surprised how well made the Genmax is and think it will provided years of great service. We purchased this product as the emergency back up generator for our whole house. This handled our 5 ton air condition with no problems. We did have a soft start and interlock system professionally installed by the electrician. We live in the Houston area. Natural gas will be our preferred fuel source. Would like to see a custom Genmax dust cover included.

I only have 5 hours on it for the break-in so far. It doesn't come with the ATS cable, but I am not going to use that anyway. The air filter is really wedged in there, not the easiest to open and remove to get it oiled. Plus, the plate behind the air filter to the carb intake fell out and was a little difficult to get back in properly. The oil strainer is also a little difficult to reach. Other than that, it performed well on my break-in runs up to 4kw.

The GM5500XID has blown me away with how reliable and powerful it is. It starts up instantly, runs smooth, and handles everything I throw at it without struggling. The build quality feels heavy-duty, and the noise level is much lower than I expected for this size generator. I’ve used it for work, home backup, and even on the go — and it performs flawlessly every single time. Fuel efficiency is great, makes it super convenient. If you want a generator you don’t have to worry about, the GM5500XID is the one. Highly recommended!

I have yet to use this generator in anger but I have run it once a month for 1/2 hour to test my whole house backup system for the last several months. I run 240 volts from the 50 amp plug to a 50 amp whole house interlock. When I got it, I ran it from a 100# propane can and it ran well on that. I have just installed a 3/4" NG QD on the side of my house (which a certified plumber hooked up and tested) and ran the generator this month on NG. I plan to use the propane can as a backup fuel source going forward. I have not tested the generator with gasoline yet. It starts right up from the propane but takes a bit to start from the NG line as I suspect it needs to purge more air from that line as it is larger (3/4" with 1/2" adapter) and longer (20 ft.). I was able to run my home's 3 ton AC unit (with soft start) this summer with this generator. About the highest steady load I have seen on it with NG so far is 5700 Watts. I had low idle On and the lights momentarily dimmed when my 4000 Watt water heater kicked on but the generator responded quickly and automatically bumped up the RPM to meet the demand.

Fuel efficiency is impressive I got several hours of run time on a single tank, and the noise level is surprisingly manageable compared to other generators in this class. The outlets are conveniently placed and include both 120 V and 240 V options, which made hooking up my tools and home circuits easy.

Worst customer service I have ever delt with. On the phone for 35 min. and got cut off! On phone again talking and explaining my issue and they cut me off again after 30 more minutes!! Sams obviously has call center in India or somewhere. Horrible!! I won't be renewing my membership!!!!