I am starting to think that maybe Micheal is correct in some cases, maybe many cases about people not setting up the carburetor correctly. Now this isn't to say that the carb is good, it is not. But the engine and carb do work. NGH instructions say to set the carb low speed needle to about 4 turns out and the high speed to 1.5 turns out. Later in this thread someplace (if I remember post #64) Micheal stated the low speed should be 6 turns out. Anyway 6 turns works for me.

But NGH could still have quality control issues and have sent out defective parts, so it is hard to say if everyone will be as successful. Some people did get carbs with defects in them as well as defective pump/regulators too. Now I did try mounting a Walbro carb on a engine and that worked pretty good actually, but it is a bit ugly with a carb almost as big as the engine itself. Lately someone elsegot a Evolution 10cc gas engine carburetor and made a adapter shim for the NGh engine to fit the Evo carb on it and the Evo carb worked well on the NGh engine too. So that is another way to do it too.

Also the carb's idle speed setting is with the carb throttle open about 1/2 open. Now this is odd, but it does work if you do that with the carb. The engine also tends to spit fuel a lot back out when running, but that is quite normal actually. I see many high performance glow engines do the same thing as well as some gasoline engines too. But the fuel spitting tends to mislead people into thinking that the engine is too rich at idle and they try to lean it out more. Plus people try to close the throttle barrel more to be like regular carbs and when you do that it just doesn't work. Now there were a few people that did some modifications to the carb and they fixed the carb to work like normal, but you don't have to do all of that to get the carb and engine to work. Now then the carburetor could have been made better, NGH didn't finish it up or put more time into it, they simply got it to work and shifted their focus to other things. They could have made it better. That 1/2 open for idling tends to really confuse a lot of people. As you know most people never really read the instructions for anything they get.

I think most problems will be in the pump/regulator unit. One may have to work on that device. The pump cover may have its center screw mount part made slightly too deep which doesn't let it clamp down properly on the diaphragm, and gasket and thus it leaks. The pump/regulator body may need to be checked to ensure the mating surfaces are actually flat and level as they could be uneven and that could cause leaks too. You can use a glass plate and some valve lapping compound to level it out better, if it needs it. The little aluminum pivot bar for the fuel inlet valve may get bent down and need straightening out or replacing with a steel pivot bar from a Walbro rebuild kit. Next the regulator diaphragm and pump diaphragm may need replacing as they may have problems. The diaphragms seem to stretch over time or get too soft. That may be because of the different gasolines used in different countries or just defective materials. But they are easily replaced using a Walbro carb rebuild kit. The pump/regulator is also sensitive to vibration and heat as well. So it needs to be isolated some from the vibration and located where it can't pickup heat from the engine. The unti does not have a little filter screen inside, so you need ot use a fuel filter outside of the pump/regulator to keep little bits of debris out of the unit where it can cause the fuel inlet valve to stick open which floods out the engine then.

Anyway, when you get it it all setup the little engines run pretty good then. Now it isn't as powerful as the more current Evolution 10cc gas engine, but the little NGH 9cc gasoline engine does work in any case and can power 40 to 50 size RC planes just fine.

Here is a picture showing about what the throttle looks like with the engine set to idle. The short video clip shows that the engine does have a throttle settings other than idle and full speed and can run at different speeds in between too.



Here is a pic of two of my planes with NGH 9cc gas engines on them out at the flying field this last weekend.


In this video I show the engine can run at dfifferent speeds other than full throttle or idle.
[youtube]http://www.youtube.com/watch?v=3Zfeq-B6e3E[/youtube]