Champion dual-mode generator # 100155 $799

I have a Sportsman 4000/3500 propane. I see no difference other than color between it and a Champion. I purchased it from Home Depot Online for $199.00. I mainly bought it because it was cheap. It turned out to be a warranty return that was sent back to Home Depot. I found the reason for the return, the neutral and ground were reversed on the 30A RV plug. It is a bit on the loud side but if I need a generator to run my trailer I am not going to be in a CG or anywhere I am worried about others. If I am in a CG it has full hook ups. My generator needs to be bonded to run the trailer and this is simply done with a 120V plug with the neutral and ground wired together and plugged in to one of the generator's 120 outlets. I also built a ground rod to jab in the ground. It's approximate 29As will run everything in my trailer with no problem but then we do not run the microwave, toaster, A/C, a heater and hair dryer at the same time. I do not understand why you want a dual fuel. My propane version is good for about 10 hours on a 20#er.
Randy