I bought the iGen 4500 for camping and for the ocassional power outage. I live in the high desert region along the San Gabriel Mt range in California, so, I purchased the high altitude kit for 3000-6000 ft. Westinghouse has an excellent tutorial video that leads you through the process step-by-step to swap out the carburetor jet. FYI, I labeled sandwich bags with each step, which helped in not mixing up hardware and reassembling the panels.
We finally got to use the iGen 4500 on a camping trip last week, and I can't be more pleased with its performance and at how quiet it is. It started right up, but I especially love the remote control. A friend in our group was so impressed with it that he said he's looking for a smaller, easier to move generator and decided to purchase the dual fuel model.