sandal

How good are the carbs on these engines? There are quite a few videos on youtube, but most of the engines seem to run very rich in the midrange. Can they be tuned to run smoothly, or are the carbs a step down from a glow engine? (OS AX, Irvine etc.) I fly at low to mid throttle most of the time, and a smooth midrange is important.

earlwb

I was normally flying around at full throttle most of the time. But the carbs on the NGH engines would run OK in the mid range for me. As I would throttle back for getting into a landing pattern to land and for shooting touch and go's. Or having to wait for my turn to land, et cetera.
Although I do have a Evo 10cc gasser engine, I haven't done anything with it yet.

The small gasser engines use spark ignition which can let them run a little rich through the mid-range without problems. So they tend to work fairly well at lower throttle speeds. Once you have the idle setup and the high speed adjusted the mid-range throttle works OK. The fuel regulator on both engines does pretty good at keeping the fuel flow constant, so the engines run well with the regulator on them.

But you might have to tinker with the pump/regulator on the NGH engine to get it to work good. The Evo gasser 10cc engine doesn't need any tinkering,

Anyway I really don't remember any issues with partial throttle settings with the little NGH engines. So it must have been working OK.

I would suggest using the Evo 10cc gasser engine over NGH engine as it doesn't need to have any tinkering done to it. Plus the Evo engien has a needle bearing big end on the rod. But the NGH engine works well if you don't mind having to fix the pump/regulator unit. The carbs on both engines worked well, no issues really.

Turk1

If you have some skill,you may play the LSN profile to achieve a good midrange for your taste on a NGH carb.But before, as Earl mentioned,you may need to play with pump/regulator also.

jerdavis

My Feedback: (3)

My experience with one of each engine: The Evo 10 carb is excellent with good adjustment resolution, both low speed and high speed and a good mid range.

The NGH 9gt carb works poorly, difficult to adjust, and a very rich mid range that cannot be adjusted out. This carb seems to be a copy of a glow carb. I swapped it for a Super Tigre .60 carb, which worked better.

JD

sandal

I wonder if all of them are like that. Maybe you got a bad one. On the other hand, most of the videos of the GT9 show the same 'characteristics'. Even in videos posted by the manufacturer or distributors, the engines are way too rich in the midrange. I wish they would show us how the engines run at all throttle settings, instead of just opening the throttle fully and showing us the tachometer.

earlwb, How difficult would it be to fit a small walbro carb to the Evolution 10cc? If I remember correctly, you had a walbro on a GT9? I don't have the skills or equipment to make any parts, but if I could buy an adapter to mount the walbro on, I would probably manage to drill and fit the pressure tap. :-)

earlwb

Well since no one has complained about the carbs on  the EVO 10cc gas engines, I don't think you would have a problem with them. The carbs on the engines work OK.

Yes if one really wants to, they can mount a small venturi bore Walbro carb on the engines. You need to either make or find someone to make an adapter for it. Just like I did on a NGH 9cc gas engine already.  But it isn't aesthetically pleasing to many people. It does work though.

I think the issue with the NGH 9cc engine was people trying to get the carb to work like a normal carb. Idle speed is with the throttle about 1/2 open. But people were trying to get it to work with idle at almost closed. I tried it like that too, and it just doesn't work. Once you just go back to leaving idle speed at 1/2 open then the carb works fine. My engines worked Ok at speeds in between idle and WOT, but I never really flew my planes at those speeds much. Anyway 1/2 throttle is idle, 3/4 throttle is 1/2 speed and full throttle is wide open. The NGH engines also tend to spit fuel a lot so people tended to confuse that with it running too rich, when it fact it wasn't rich at all. I had idled one of mine for several minutes with it spitting fuel and it kept on running just fine and when I increased throttle it picked on up no problem too. But the carb isn't all that great, I think NGH could have done a better job on it though.

Most of the problems people had was with the NGH 9cc engines was with the fuel pump/regulator unit. You may or may not have problems with it. Use a fuel filter to help avoid some little tiny debris getting into the regulator inlet valve and causing it to stick open and flooding the engine out.

sandal

earlwb, Turk1 and jerdavis, thank you for the info.

One more question: Does the Evo 10GX carb need adjustment every day like a glow engine? Or is it (more or less) set-and-forget like a Walbro?

earlwb

Actually for the NGh engines, after I set the needle, I just don't need to touch the thing afterwards any, But when winter arrived I needed to tweak the needle slightly. I assume when it gets warm I'll need to do it again.

sandal

Does it lean out during the flight like a glow engine, so that it has to be set a little rich when the fuel tank is full?

earlwb

NO the NGH engine doesn't lean out in flight, if everything is working. It has a pump/regulator like they use on Walbro carbs, so you can set it and it won't lean out.  But with major seasonal weather changes the air density changes, the temperatures change and the gasoline/oil mix becomes more dense and more thick or viscous, so you have to tweak the needle slightly. I think it is like a click or two on the needle, nothing much.  The same thing happens with my other  Walbro carb equipped gas engines too.

I haven't run my Evolution 10cc engine or flew it in a airplane yet. So I can't say for sure about it.

sandal

Great info, thanks!

rc34074

My Feedback: (5)

Hmm- I may be wrong but the pictures I have seen of the NGH engine show a carb with a regulator but there is no pump built into the carb. But I now see that NGH supplies a separate pump for this engine - weird. The main thread about this engine has pictures where thir huge pump is mounted near the engine, which I guess is what would work best. It looks like they took a walbro pump and packaged it separately to get the pump feature. So how far from the engine can you mount the pump and have it work well? Also it seems like it would be pretty hard to mount the pump in a lot of 40 size planes and look "normal", so why couldn't you just leave off the pump? And use a pressurized tank like Evolution did?

Ed

earlwb

The Evolution 10cc engine has a regulator built into the carb. For some unknown reason NGH opted to put the regulator into a separate unit along with a fuel pump. The NGH pump/regulator can be several centimeters from the carb, but it works better if you have it close to the carb. Thus to emulate what Evolution has done, you'll need a regulator for the carb, maybe a Cline regulator would do the trick. I haven't tried it yet.

In one plane I have the NGH pump/regulator as close as I can get it to the carb, it sits on a padded shelf so it doesn't move around too much, some velcro strips hold it loosely so it doesn't pickup up too much  engine vibrations.  In another plane I have the pump/regulator behind the engine loosely held in place with sme foam padding and velcro strips. But having the pump/regulator behind the engine and farther from the carb results in a little leaning out at the bottom of a high speed loop. The other plane doesn't have that slight leaning out issue.

The NGH pump/regulator unit works, but you might have to fix it if you have any issues. It is vibration sensitive in that the vibrations seem to cause excessive gas bubbles inside the unit, and the gas bubbles travel to the carb resulting in erratic running of course. I think it is the gasoline vaporizing and not aiur bering sucked in.  Even though the NGH carb could have been made better it does work OK, but idle speed is really 1/2 open throttle. Changing the needle profile can help with that though.

sandal

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rc34074

My Feedback: (5)

Earlwb -

I am a bit confused I guess- when I look at the ngh carb it has a square section on the front of the carb just like the 10gx carb. That is where the regulator is on the 10gx. So it looks to me like the ngh carb has the regulator right on the carb and the pump is in the separate cube.

Ed

Turk1

No, there is nothing in NGH9 CC carb except a useless diaphragm,it is a typical glow carb.That is the flaw with that engine.The regulator and pump are built in that separate unit.

rc34074

My Feedback: (5)

OK- Thanks - then I wonder how the ngh 9cc engine would run with the 10gx carb on it and possibly eliminate the ngh pump/regulator unit?? Or has someone already tried that?

Ed

earlwb

I don't think the Evo 10cc engine has been out long enough to have parts availability yet. But maybe when they gets some parts in, someone will try it.

Turk1

Before all I really wonder if anybody may try NGH 9 CC with a muffler pressure system without reg/pump unit.
I should have tried it but my bench doesnt allow me to mount the glow type muffler on engine.

earlwb

I saw someone at our flying field do that with a NGH 9cc engine, he tried muffler pressure without the pump/regulator. It seemed to work, but he was having problems though. But I don't know if it was related or not. I wasn't really paying attention at the time.


Now then a year or so ago, I did try that with the first engine and it didn't work. It might work with a regulator in between there though. I was thinking about revisiting it by using a Cline regulator along with the muffler pressure.

pulse60

Hi all I've been trying a ngh engine for a wile now and I have decided that I would try the evo carb on the ngh picked one up fo $60 was very surprised how quick it came only order it last week any way ill let you know the results as soon as I've had a chance to try it

Turk1

I guess you will have a good running engine.Good luck.Careful on oil ratio.

Basil Yousif

My Feedback: (3)

I just got my Evo 10cc engine in a World Models 46 size P-51. I hadn't run the engine but for only a minute on the stand. I adjusted the engine on the ground but when it got into the air the plane had very little power. It kept making a cutting out sound then it stopped after a few minutes of flying time and I did a dead stick landing. Should I run the engine on the ground for more time to break it in.

jerdavis

My Feedback: (3)

Basil,

Sounds like your spark plug cap may be loose on the plug or the ignition battery is too low.The spark plug cap requires a pretty good push and a firm twist (be careful not to break the plug) to properly lock on the plug.

Jerry

jerdavis

My Feedback: (3)

I tried the NGH 9gt with muffler pressure, a cline regulator with crankcase pressure, a Supertigre carb, and a walbro carb. I cured the fuel draw problem by replacing the NGH with an Evo 10GX.
I then put the NGH ignition on an OS 46 AX, witch runs beautifully on gas(using a Supertigre carb), and threw away the NGH.

Jerry