I have one, I just got it in, but I haven't run it yet. Maybe this weekend. I expect it to work OK, so after some bench running, I'll put it in something.
I plan on using Coleman Lantern fuel or camp fuel in it as the Naptha doesn't stink as much as the gasoline does we have here in the USA. Nowadays our USA gas has a really annoying smell that bothers me, many years ago the gasoline smells didn't annoy me like it does nowadays. I really hate taking the gasoline can to refill at the gas station for my lawn mower, etc as it just stinks up the car really bad for the drive home. Also our USA gas has ethanol in it and in some areas a lot of ethanol in it and the ethanol may be damaging to the pump and carb diaphragms and valves. I remember a lot of guys complaining about their gasoline RC engine's pump carbs going bad fairly fast using our USA gas in them. So apparently the RC gassers have different pump parts inside than our weed wackers and lawn mowers, chain saws and leaf blowers do. As our utility engines don't seem to be affected by the ethanol in the fuel. So maybe the pump carbs having been designed and tested in China and made in China are using rubber parts and or diaphragms that don't work well with ethanol in the gasoline. The gasoline in China is different than our USA gasoline.
The engine I got smelled as though it had been test run at the factory. I found from a couple of others that NGH is indeed test running the engines at the factory. So that is pretty cool. Previously only Fox Manufacturing was the only company that test ran its engines. So NGH is pretty unique in that respect.
Yeah I had seen at our flying field and read about others having problems with Saito Gassers too. So it isn't unique for such problems to happen with something new.