Our owner's manual indicated the viscosity of oil required varies with the ambient temps when generator is predominately operated. We use 15W-40 which corresponds to ambient temps of 10 degrees to 100 degrees. We always run synthetic and currently have over 700 hours on our unit.
Break in period requires a low wattage device and a fan will do the trick nicely. Generators tend to run better the more often there are utilized, they should be exercised regularly if they don't get much use.
Some generators come with poor quality spark plugs, getting a better made spark plug is wise and carrying an extra wouldn't hurt. Haven't heard much feedback on the Smarter Tools genny available from Costco, it would be nice to hear some feedback as to your experience with this new entry in the portable generator field. Good luck and enjoy your new generator.
