Originally Posted By: meep
did you go with the honda or yamaha? I do recall my yamaha ok'ing a 10-40 wt, while the honda called for 5-30.
if it's the yami, I'd likely side with the rotella 5-40, or a heavier good 10-30 such as syntec or Penzoil. I am one of the few folks here who has had some unhappy OPE with mobil synthetics, and it was in a honda that was run hard... so i shy away from M1.
the honda will REV... under load it will throttle up to 4400 rpm sustained IIRC. don't run a 40 wt in that. Use a quality oil that can flow and not bog it down or stress the splash pin.
The yami revs to 3600 IIRC, so it relies on more torque for a given output... hence the thicker oil. It also has a heavier gen head, so the combustion impulses hit the bearing surfaces harder.
i wouldn't worry too much over zddp. all the quality oils out there are good. And if you do an anual or 50 hour oci, whichever comes first, you should be fine with about anything.
More important-- due a couple of short OCI's when it's new, on regular dino to break it in and flush out any manufacturing debris. Run different loads on it. It can take them a while to break in--- I'd consider the first 40-50 hours on some of these engines to get nicely settled, but the first couple of changes are critical for getting out the small metal sparkles.
Almost all generators run at exactly 3600 RPM, unless they have a "no load idle option". Whether you run a light bulb or a toaster the generator runs at the same RPM, it has to to provide the proper voltage at 60 Hz. Now when its loaded up, the governor works to keep it at 3600 but the engine will be putting out a lot more HP and you can hear it. So the engine does not REV up to 3600 RPM, it always run at that RPM.
Its possible some run at 4400 RPM, but again, it would then always run at that RPM regardless of the load.