Found a large group of followers of the Honda EU2000 on Yahoo Groups. A few of them ran consumption tests and posted their results though the data is confusing. None of them got 15 hours at 1/4 load (more like 9.6 as Honda has stated), some got 4+ hours at nearly full load with ECO on, but only 2.5 hours with ECO off (which doesn't make sense).
You have to join to see the excel spreadsheet.
Here's a thread where a guy got 4.5 hours driving a 1500W heater
This guy claims 12 hours driving a furnace
Wayne Dohnal wrote:
Talking about the "camshaft" is even an overstatement because it's just a single lobe on the side of the belt sprocket.
I thought there was a lobe on the other side, but you're right - there is only one lobe and it first actuates the exhaust valve then the intake.
