With the Hondas I’ve found more issues with sensitivity to dusty fueling conditions. Every one I’ve had eventually develops a surging throttle condition, including my fairly new eu2000i. And in every case, cleaning the jet and installing a fuel filter makes the problem go away.
in the eu2000, there’s not much room for a filter, and the gas line is like 1/8”. I used a metal r/c filter designed for gas in it, and sealed its threads with seal-all as an extra precaution. Of course, when I did this, I also had to clean the jet because refueling on a dusty day is all it took.
with a heavily used mower, M1 5-30 was too thin when mulching in the southern heat here, and the engine was damaged over time. 10-30 solved the problem and the sparklies stopped showing up in the oil. It kept increasing start up smoke and consumption until I changed to 10-30 and it remained the same, but didn’t get worse, after that. Based on that, I won’t get thinner than a 10-30 in ope.
oh, and I’ve run that eu2000i nonstop for days following storms. Using synthetic oil, a week is fine as long as you check it.
Not all Honda engines use the same oil change maintenance schedule!
Your eu2000 is 100 hours or 6 months...
My EG2800i is 50 hours of 6 months under "normal" operation and 25 hours or 3 months under high outside temps or continuous / heavy use
But IMHO it is foolish to run your eu200i nonstop for a week without changing the oil. 168 hours is way over what Honda recommends.
It takes .42 of a quart so I will guess about $2 to change the oil.
Are you really that lazy and cheap?
I know changing the oil in the eu2000i is a little harder than some units - I have a similar 2000 watt unit and you have to pick it up and pour the oil out of the fill hole - but even the first time I did it it only took a few minutes.
The thing is - not changing the oil in your eu2000i will most likely not cause a total failure - it just reduces the life.
So do proper maintenance and it will last for decades of occasional use abuse it and it will start smoking, fouling plugs and lose output.
Your unit your choice - but I take a totally different approach to maintenance.
Many OPE manufacturers now recommend 5w30 - and since both 5w30 and 10w30 are 30 weight when hot it really only matters at start up.
The reason your mower was starting to smoke wasn't because you used 5w30 - it was because you didn't change the oil often enough. Oil gets contaminated and it causes excess wear on the rings - worn out rings from poor maintenance can be helped by using a heavier weight oil - but the damage is already done - using a heavier oil just helps cover up the problem.