That short a set time you should not have had hard start issues.
However with ONAN it is a carb engine, and the gasoline evaporates.. It takes time to replenish it in the bowl.. I think that is the issue.
My genny initially was hard to start.. Then I re-read the manual
Press and hold STOP till the light comes on (in fact keep holding it for like 10 or 30 seconds) then press START.
Or, "Tap" start.. let it sit for about 30-60 seconds THEN Press start.
Either method seems to fire it up much faster.
Got to do that next week, Normally it would be tomorrow but I'm hoping to haul this "Shack" to the shop for an engine swap next week. So..... I'll only have minimim 120vac there.. Will need to "Augment"
