I bought this as a backup to my other generators and as small portable power.The unit is of excellent quality its quiet and extremely fuel efficient.I Bought this over the Honda even tho the Honda has more power and a much better service network.Well I have a small engine repair shop [...] so, I bought the service manual for 12.50 online (pdf)The hard copy is 80 bucks on the Yamaha site. I use a tablet in the shop for manuals so a pdf is great.The nearest Yamaha service is in Kona (200 mile round trip) screw thatThe Honda is also a great unit "BUT"What impressed me with the Yamaha over the Honda is as follows:1. All metal engine parts(the Honda has a plastic oil slinger and when that fails the plastic cam soon follows. The Yamaha has an old fashioned metal dipper on the bottom of the crank)2. The Yamaha is 200 bucks cheaper3. The controls are on one side4. It has a fuel shutoff(actually the Honda does too but it also kills the engine so you can't run it dry "actually you can unplug the kill connector and do so too")5. It is a little lighter6. The shape is smart and has a smaller foot print.7. The Yamaha has duel metal cams w/ push rods( The Honda has a belt driven single cam and it is plastic)8. The Yamaha has an iron cylinder sleeve(The Honda is not lined)9. Yamaha has a fuel gauge which is really handy and it helps you when you are fueling the unit.10. The Yamaha will run a 400 watt load on 1.1 gallon of fuel for 10.5 hrs where the Honda only for 9.6 hrs.11. the Yamaha meets C.A.R.B compliance up to 300 hrs where the Honda only goes 150 hrs.( this may speak volumes about the over durability)12. the Yamaha comes with 12v charging cables, Honda you'll have to buy them at about $13.00 bucks.13. The Yamaha has auto warm up feature.14. The Yamaha is easier to work on.My start up procedure:1. added 4ml oil Mob-1 10w30 with some molybdenum2. pulled the plug checked gap, squirted 1/2oz of Mobile-1 mixed with moly and zddp cranked it w/o plug for 20 pulls, appliedanti-seize to plugged re-installed plug3. removed to spark arrestor screen and slung it.4. oiled the foam air filter5. Added 1 gallon of non-ethanol 89 octane gasoline w/ a squirt of Techron.Turned the fuel on and pulled the choke made sure the o.f.f.o.n. switch was in the o.n. position.Waited just a while so the carb bowl would fill and it cranked on the 1st pullI ran it to equalize my battery bank but made it only charge at 30 Amps up to 32.8V dc that only drew approx. 984 watts for 2 hours.after that I let her run all might on eco mode.The next day I changed her oil with Mob-1 and checked the used oil for metal with a super strong neo magnet.There was no perceivable metal at all.I also installed an hour/tachometer.Changing the oil is really a snap. I shake my head in wonder at folks that don't seem to agree.Just use a measuring cup 400 ml/ 13.4 oz and tilt the unit 45 degrees when filling. For pouring it out, just pour it out there is a little ledge that keep the drips contained and you just wipe that with a shop rag.I will change the oil at 50 hours intervals. I am 50 so I figure this bad bear will last me the rest of my life.Notes:Always shut the fuel off as any bowl type carb will leak if the float sticks.Never use ethanol laden fuel in any engine except in emergency.always use a little Chevron Techron in 4 stroke fuelOnly use synthetic oil (any brand)###############UPDATE######################posted a pic of some running numbersKwh/gallon (1.1) over 7.82Kwh in 5.33 hours of running various loads during charging.alsoI ran 1 tank 1.1 gallon in eco mode w/ no load and she ran for 20hrs and 12min. Wow!