Quick question....How long(seconds) would you say it takes to start your generator? Ours takes between 20-25 seconds and our dealer says its normal. They say the gas has a long way to travel before it gets to the fuel pump. I tried priming for different lengths of time but no difference. This is on a new 2016 ACE 30.1 that we have owned for 10 months and its been this way from day one.
You may want to go directly to the gen and prime it there and make sure you are hearing the prime, you could also pull the fuel line and see how long it takes to for the fuel to get to the carb.
Another thing you may want to start using Ethanol fuel treatment in the rig, I know first hand that todays fuel eats away the Onan carb parts, as I just sold my last Toy Hauler that after one time I missed using the fuel treatment it got gummed up and wouldn't start.
Our 4000 sometimes takes over 30 seconds after priming. The unit times out after 30 seconds, we wait about 5-10 seconds and then it seems to start right away on the next attempt. It always takes longer when the unit has not been started in a day or so.
We spoke to an Onan rep at one of the many RV shows we've been to and he recommended that the unit needs to be primed for 20 seconds before starting (also found that recommendation in the Onan user manual).
I am just glad that it starts even if it takes what is considered a long time. I believe Onan and Thor recommend starting the generator regularly which would also contribute to how long it takes to start the unit.
Tom and Lisa
2015 Challenger 37TB
2015 Ford Taurus toad