Frank,
I read you're posts about the Simjet 1700.
I was wondering if you ever replaced the propane solenoid?
If that valve won't open, it won't start, although it can be manually opened if you can reach the button on it.
I have a 1700 with 148 flights on it and it runs and starts great.
The only problem I run into is the Festo propane sol gets dried out from the propane, it needs a few drops of 3in1 oil every 4-5 starts.
Just wondering?