Thanks for requesting me!
With this set, unless both the stator and rotor happen to be shot, definitely fix it. It's too bad you have already replaced an expensive controller.
Code 36 is almost always fuel related.
As far as the shutting off when you release the start button, this is the single most common complaint with Onan. It has several causes, but is most often caused by the set not producing electricity.
The first thing you need to do is to verify whether the set is actually producing or not.
Remove the control cover to access the circuit breakers. Set your meter to VAC and connect the negative lead to a good ground. Connect the positive lead to the back of a circuit breaker on the wire marked T1. Press and hold start for about 5 seconds.
How much voltage is being produced?
I am also assuming you have checked the oil level to ensure it is full.
You are correct there. You should not even be able to turn the rotor by hand. This belt is very tight.
I honestly have not had an issue with the drive belt on any of these units. When Onan first came out with the vertical configuration, I thought they were crazy - just something else that can go wrong. But I have yet to see one fail.
If the problems are caused by a loose belt, it should be giving either a Code 13 - Under voltage or a Code 15 - Under Frequency, or both.
Recheck your code again.
Also check your flash voltage while cranking. Set your meter to VDC and connect the positive lead to the lower brush wire, and the negative lead to the upper brush wire while cranking. You should see at least 12V, and ideally 20-30V.
Glad to hear it.
As I stated earlier, I really don't like these vertical configurations. All those extra moving parts are just something else that can go wrong. Give me a horizontal direct drive any day.