I have a JJ1800 I bought a couple of months ago. I ran it fot the first time this past weekend. I have the semi- auto version. My first start attempt I couldn't get the propane lit, even with what I thought was a freshly charged Ni- starter. I changed the plug to the same type I use in my other turbines and it lit. It idled at 30k rpms as advertised. I could only get 96k rpms at full throttle as opposed to the advertised 115k. I almost certain that this was due to my fuel pump/ ecu battery not being fully charged.The HDT was indicating around 6.7 volts at full throttle. Also, I hadn't charged the battery since I had it. I ran it just to make sure it would run. I'll run it again this weekend with everything fully charged and post my results as far as full throttle rpms. I guess in a nutshell, I'm very happy with it. It appears to be a good engine. It's a gas guzzler unlike my Wren.