GreaTOne_65

I am looking for some input about the NGH 17. One of my flyin' friends, has 2 of them, and they both have a problem dying on down lines. We have done seemingly everything we can do, but still the problem persists. Any one have any ideas/cure?

Thanks,

Dale

JohnB96041

Try making the fuel line that goes from the fuel tank to the carb longer. Make it long enough that it will loop at least once before going to the carb.

GreaTOne_65

Thanks, John, that is something we haven't tried. I sure hope it works, this has been quite an ordeal, as it seems nothing seems to work.

Turk1

Felt clunks in tanks?If not,change them with felt clunks.

GreaTOne_65

Thanks, turk. We've done that. Your reply is appreciated.

earlwb

I was thinking that there may be some subtle air pressure changes going on inside of the cowl on the airplane. The fuel pressure regulator diaphragm in the carburetor uses the atmospheric air pressure as a reference point. Thus in certain aerobatic maneuvers the air pressure inside the cowl changes and it affects the fuel pressure in the carb, which of course affects the fuel flow into the engine.

I would suggest setting up a fitting and tube like Pe Reveivers discussed in his thread about it here http://www.prme.nl/forum/viewtopic.php?t=205
and
http://www.flyinggiants.com/forums/s...ad.php?t=36023
This would keep the reference point for the fuel pressure regulator more constant which should help alleviate the issues you are having.

GreaTOne_65

Thank you, Earl. I am aware of the silly things that happen inside a cowled in engine, the problem, is the planes the engines are in, don't have cowls! LOL!! I thought at first, maybe the hole in the plate might make a difference, so they were changed, and that didn't solve the problem. It's beginning to feel like these little buggers have some kind of "design flaw", it's not possible, but boy, it's getting close to that.!

Dale

Mikola

NGH has always been junk, buy Evolution engines from horizon hobby

Mike.

earlwb

Well I have a NGH 17cc gas engine in my big Superstunts .60 plane. It seems to work just fine for me in the plane. I don't remember it ever wanting to die in a nose down attitude though. The engine is all open in this plane too. Of couse in the Superstunts plane one only needs about 1/2 to 2/3 throttle to do most every aerobatic manuever as it has so much wing area and is very light weight for a big plane with a 80 inch wing span. It doesn't seem to want to spin fast although it does do spins, it needs more aileron surface area as they used some of the span for flaps. I am thinking about changing the flaps to flaperons. Several other people bought NGH 17cc engines after seeing mine work out OK. But I haven't seen them fly their engines yet, we haven't converged at the flying field at the same time so far.

But on the internet I have read of a couple of people having connecting rod failures though. I use Stihl Ultra synthetic oil and maybe that helps keep the rod lubed better. Hard to say though.

Now in my GP Big stick I am running a NGH 9cc engine with a Walbro carb conversion and if I take the plane into a full throttle power dive, when the plane reaches a certain airspeed the engine suddenly leans out and quits. I got to studying it and the hole in the regulator cover is just inline with the rear edge of the spinner. I surmised it might be building up some air pressure right there behind the cover causing the engine to lean out at higher speeds. I put a fitting and a tube on it and routed the tubing inside the fuselage and it quit dying on me like that in a full throttle power dive.

grossy2

I had a few tunnig issues with this Engine. I put a Velocity stack on it and all's good.
Cheers

Turk1

Hi Mikola,all such engines having Walbro or imitation carbs which is the source of such problem.Its not the engine,it is carb(or fuel feed) causing this.There is no reed system on this engine to be another possibility.
I also think either regulator pressure fluctuations or pump check valves diaphragm may be the cause.

dan v

anyone use Benol racing 2 stroke oil? I'm thinking about using it for my new NGH 17cc.
Was thinking about using it because it has caster in it.
Thank you Dan

GreaTOne_65

Dan, I would advise you not to use, a castor based/castor blend oil. Castor, does not like the higher temperatures generated by gasoline engines, it will stick the rings to the piston. Ask me how I know? Stick with a good brand of two stroke oil, the synthetics, work quite well. Last year, I used TruFuel, a two stroke fuel, available at Lowe's, Home Depot, Tractor Supply, and other big hardware stores. My reason for using that fuel, because the ethanol seems to raise hell with the diaphragms. I think it was the right thing to do, as I had zero problems with the diaphragms.

dan v

1- Thanks GreaTOne-65! I will use the Trufuel 40:1 mix in my NGH 17cc, but my manual calls for 20:1 for break-in. So I went on their facebook and asked them what oil to use to mix to get the proper ratio.
2- Benol is the oil recommended for my new Russian Norvel GX .40 BB sport engine. No ring or diaphragm. It's a gasoline 6.1:1 engine with a turbo OS plug. I've started it a couple of times, so It's not broke in yet.
But so far I like this engine, seems like It's as powerful as a .46 like they say.
Thanks again
Dan

SkidMan

My Feedback: (17)

I have a NGH 17cc and I would not dare run 40:1 anything in it. It, and some other smaller engines, use bushings rather than needle bearings on the connecting rod. Because of this they should be run with more oil. 40:1 high quality synthetic in my larger engines? Absolutely.

Keep in mind that the manufacturer recommends high-qual synth at 25:1 after break-in for this engine.

As GreaTOne posted, even though modern carbs, etc. have a higher resistance to ethanol, I run ethanol-free gas. It is easy for us to find in Florida. You can try pure-gas.org to see if you have a source near you.

Paul

earlwb

I use Stihl HP Ultra synthetic oil in my fuel for the engine. If the oil is not a really good syntheitc oil for air cooled two stroke engines, I would not use it. I mixed it 25:1 for the engine as the connecting rod does not have needle bearings on it. I would not go less than 32:1 oil mix though. But 32:1 may be risky still for the connecting rod. But maybe after a couple of gallons of fuel has been run through the engine then the less oil ratio may work OK. I would stick to the 25:1 fuel to oil ratio. After break in 25:1 is the suggested fuel to oil ratio they have in the instructions too. I ran 20;1 for quite a while for the break in too.

dirtybird

My Feedback: (5)

There once was a poster on RCU that claimed it did not make a lot of difference which oil you used as long as it was made for air cooled two stroke ingines and mixed according to the MFG's specs. He was one of the fellows that flew the drone across the Atlantic before Maynard Hill did i.t.
There was another poster that did a lot of work for Cornell university flying drones to snare bugs for their research. He tested a lot of oil over a long period and came to the conclusion Pensoil air cooled was the best. The only trouble with the Pensoil is that its very hard to find now

earlwb

I have run some gas engines with other brands of oil and the bushed rods would fail on them, if I didn't use a really good oil. The cheap oil didn't work out. Usually I also had a lot of carbon buildup on the engines as well. With some engines using needle bearings there still was a lot of carbon buildup in the engine.

In my experiences: Amsoil worked but mixed at normal levels leaves a lot of carbon on the engine. That suggested AMSOIL 100:1 is not for model airplane engines. Stihl HP Ultra works good and leaves a lot less carbon residue on the engine. Redline works well too. Also if the engine can use it the Klotz Benol works too. But don't use Klotz Benol on four stroke engines though as it is castor oil based. But I use these oils mixed at what the engine manufacturer suggests to use.

I have seen the NGH 17cc engines fail using cheap oil. But you don't have to listen to me, you can try whatever you want to use at whatever mix ratio you want to use. Maybe it will work fine for you.

dan v

Thank you very much SkidMan.
Will the NGH 17CC start ok by hand flipping when it's mounted inverted?
Dan

SkidMan

My Feedback: (17)

I certainly used a starter for the first start of the day, and most of the time. My NGH-17 is mounted upright so I can't give you any extra help there. I don't have any reason to believe that once you have the needle valves set properly that you will have any problems inverted.

Someone else with one can probably answer this.

Paul

earlwb

I never tried starting one inverted. You might put it on a engine test stand inverted and have a go at it to see how it does inverted. The larger gas engines tend to be much easier to start inverted. For example, I cannot hand flip start my 58cc gas engines right side up. But the same engines are quite docile inverted, with super easy starting and run great like that. So there is a good chance that the NGH 17cc engine will be easy to start inverted. I would suggest not having them perfectly inverted, but angled a little off, so that the spark plug is not the lowest point in the engine. That way oil residue doesn't foul the spark plug so easy as it drains down into the lowest point in the engine.

dan v

Thanks again everyone. My engine is going on the new Ryan STA. It will be mounted inverted at about a 45 degree angle. The holes came already drilled w/blind nuts installed.
Dan

ramduster

My Feedback: (2)

Would this be a good engine for a four star 60.

earlwb

I don't see any reason you couldn't use it in a Four Star .60. It pulls by Seagull Superstunts .60 plane around really well and it has a 80 inch wingspan.

jstanton

My Feedback: (14)

Yes this would be a very good engine for a 4 star 60. I have mu NGH GT17 in a GP Escapade 60 and it is very close to the same size as a 4 star 60. I am using a evolution 14x8 prop and I am getting 9800ROM with it. It fly's the plane like it is a paper weight. Unlimited vertical and it will do every stunt in the book. Sorry for the inverted images. Don't know what happened.