NGH 9cc
#101

My Feedback: (3)
Join Date: Mar 2003
Location: Roseville,
CA
Posts: 990
Likes: 0
Received 0 Likes
on
0 Posts

This is the engine. It's possible that the guy fiddling with it at our field just had a early model that had bugs in it. The ratings on the Horizen website look good. It is around a .91 size reguular four stroke motor in size and weighs around the same. Should be good if they worked the bugs out of it. Same price as there Saito .91 4 stroke glow engine. It would be nice to find out if this engine can give you some power like a TT .91 or the YS 110FZ I run on glow fuel.
That video you have with the bubbles on the 9cc motor looks alot like what was happening with the JBA 15cc motor I had. Except that engine never really started except for 30 seconds and then never again. The DLE 20 with a larger than average .60 size plane worked good for me as the smallest reliable gas powered setup I don't know about these conversions they seem up and down in reliability and drill a hole in your head with how noisy they are. Just guessing but it might have something to do with the gasoline carb not working to good with a small glow frame or that small spark plug having to ignite that gasoline /oil mixture that gunks up easily. Bigger conversions don't have alot of these problems possibly becasuse the gasoline/oil mix gets in and burns easier. Who knows they might have worked these problems out with this engine hope so!!! $200 is way too expensive for this engine especially if you get a Lemon. When there shown to be reliable and around $100 tha's when I'll get one.
That video you have with the bubbles on the 9cc motor looks alot like what was happening with the JBA 15cc motor I had. Except that engine never really started except for 30 seconds and then never again. The DLE 20 with a larger than average .60 size plane worked good for me as the smallest reliable gas powered setup I don't know about these conversions they seem up and down in reliability and drill a hole in your head with how noisy they are. Just guessing but it might have something to do with the gasoline carb not working to good with a small glow frame or that small spark plug having to ignite that gasoline /oil mixture that gunks up easily. Bigger conversions don't have alot of these problems possibly becasuse the gasoline/oil mix gets in and burns easier. Who knows they might have worked these problems out with this engine hope so!!! $200 is way too expensive for this engine especially if you get a Lemon. When there shown to be reliable and around $100 tha's when I'll get one.
#102
Senior Member

ORIGINAL: boostoman
Alright guys i thought i might make a vid since it would be alot easier to explain to everyone my issues with my engine. they are three main issues im having
1) bubbles coming out of the carb when starting up which is causing issues when starting
2) engine cutting up at full throttle
3) alot of fuel residue and blue smoke coming out of the exhaust. which I think it's due to having too much fuel: oil mix (i''m using 20:1) which i will try to use my normal 32:1 fuel that I use on all other planes to see if it makes a difference.
my setup 11x7 prop. with 4.8v on the ignition
http://www.youtube.com/watch?feature=player_embedded&v=EMfc4_zQLdc
Alright guys i thought i might make a vid since it would be alot easier to explain to everyone my issues with my engine. they are three main issues im having
1) bubbles coming out of the carb when starting up which is causing issues when starting
2) engine cutting up at full throttle
3) alot of fuel residue and blue smoke coming out of the exhaust. which I think it's due to having too much fuel: oil mix (i''m using 20:1) which i will try to use my normal 32:1 fuel that I use on all other planes to see if it makes a difference.
my setup 11x7 prop. with 4.8v on the ignition
http://www.youtube.com/watch?feature=player_embedded&v=EMfc4_zQLdc
You are solve the problems with bubbles in fuel line?
Hi Mr. michaelchow
I have same situation. How I can solve this problems?
Regards
Jimmymugurel
#103
Senior Member
Join Date: Jul 2010
Location: , CHINA
Posts: 123
Likes: 0
Received 0 Likes
on
0 Posts

Mr. Jimmy,
Please visit my video house how to run it. http://u.youku.com/user_show/uid_michaelchow2099
and Please visit GT9 thread : http://www.rcgroups.com/forums/showthread.php?t=1555659, more details in.
michael
Please visit my video house how to run it. http://u.youku.com/user_show/uid_michaelchow2099
and Please visit GT9 thread : http://www.rcgroups.com/forums/showthread.php?t=1555659, more details in.
michael
#104

Ok, I can get my engines to work OK. but the fuel pumps I have seem to be sensitive to engine vibration which tends to cause the fuel to vaporize inside the pump and it looks like air bubbles going to the engine. So I isolate the fuel pump from the vibration as much as I can. I eventually went with a small box like structure and padded it to help minimize the vibration problems. Then you want to keep the fuel line from the pump to the carb quite short. The longer the fuel line the more problems you have trying to adjust the engine.
I would suggest for testing, is letting the pump hang loose and not touch the airframe on the ground, Then run the engine and see if that helps or not. if it does work for you, then you need to figure out how to mount the fuel pump to isolate it from the engine vibrations.
I do have a bit of a problem where the engine tends to run rich through the mid range and has a tendency to lag before it catches and peaks out on power. So sometimes the takeoffs tend to be interesting and longer on the rollout. But when the engine catches and peaks out, it stays like that in the air really well.
Getting the actual air bubbles out is a pain, so I have to move the plane around so that the pump has different angles to it to work out the bubbles before I fly it. Usually that first engine run of the day is the tricky part getting the bubbles out. but after that, once the bubbles are cleared out, it runs well.
You can see in this pic where the pump is mounted close to the engine so that the fuel line is short in between the fuel pump and carb. I removed the rubber bands later and went with a loose fitting velcro strap instead, so that the velcro on the pump back was isolating the vibrations. That worked pretty well. These bubbles appear to be actually gasoline vapor and not air bubbles. The gasoline is vaporizing inside the fuel pump and in the fuel line between the pump and the carb.

Here is a you tube video of me flying the plane too
[youtube]http://www.youtube.com/watch?v=D8ITI2qMJTI[/youtube]
In this video you can see what happens if I mount the fuel pump so that it picks up the engine vibrations. I was trying the special fuel pump bracket that lets you mount the pump to the back of the engine. But just letting the fuel pump dangle loose behind the engine had the fuel pump working really well then.So I feel that the pump is engine vibration sensitive.
[youtube]http://www.youtube.com/watch?v=cyfg3tsg0qE[/youtube]
I would suggest for testing, is letting the pump hang loose and not touch the airframe on the ground, Then run the engine and see if that helps or not. if it does work for you, then you need to figure out how to mount the fuel pump to isolate it from the engine vibrations.
I do have a bit of a problem where the engine tends to run rich through the mid range and has a tendency to lag before it catches and peaks out on power. So sometimes the takeoffs tend to be interesting and longer on the rollout. But when the engine catches and peaks out, it stays like that in the air really well.
Getting the actual air bubbles out is a pain, so I have to move the plane around so that the pump has different angles to it to work out the bubbles before I fly it. Usually that first engine run of the day is the tricky part getting the bubbles out. but after that, once the bubbles are cleared out, it runs well.
You can see in this pic where the pump is mounted close to the engine so that the fuel line is short in between the fuel pump and carb. I removed the rubber bands later and went with a loose fitting velcro strap instead, so that the velcro on the pump back was isolating the vibrations. That worked pretty well. These bubbles appear to be actually gasoline vapor and not air bubbles. The gasoline is vaporizing inside the fuel pump and in the fuel line between the pump and the carb.

Here is a you tube video of me flying the plane too
[youtube]http://www.youtube.com/watch?v=D8ITI2qMJTI[/youtube]
In this video you can see what happens if I mount the fuel pump so that it picks up the engine vibrations. I was trying the special fuel pump bracket that lets you mount the pump to the back of the engine. But just letting the fuel pump dangle loose behind the engine had the fuel pump working really well then.So I feel that the pump is engine vibration sensitive.
[youtube]http://www.youtube.com/watch?v=cyfg3tsg0qE[/youtube]
#105
Senior Member

Hello,
Thanks for the help, I solved the problem on the ground. Since air bubbles in the hose, but it works well. This weekend will see how it behaves in flight.
All the best
Jimmymugurel
Thanks for the help, I solved the problem on the ground. Since air bubbles in the hose, but it works well. This weekend will see how it behaves in flight.
All the best
Jimmymugurel
#106
Senior Member

Hello Mr. Michaelchow
carburetor finally goes wrong. I opened the pump and the setting is unlike that of Walbro carburetor. My question is part 2 should be level with the pump body (2 and 3). Look in the photo.
Thank you.
Jimmymugurel
carburetor finally goes wrong. I opened the pump and the setting is unlike that of Walbro carburetor. My question is part 2 should be level with the pump body (2 and 3). Look in the photo.
Thank you.
Jimmymugurel
#107
Senior Member
Join Date: Jul 2010
Location: , CHINA
Posts: 123
Likes: 0
Received 0 Likes
on
0 Posts

Jimmy, while piston move from TDC to BDC, fuel transferred via this hole, the fuel pressure make the floater up, and pressure on spring, and then rocker arm down. when piston move from BDC to TDC, floater down and close, and rocker arm up. floater control the fuel transition rate.
So please push rocker arm, and see if spring can backspring when your finger leave from rocker arm, same level is not neccessary.
So please push rocker arm, and see if spring can backspring when your finger leave from rocker arm, same level is not neccessary.
#108
Senior Member

Hello Mr. Michaelchow,
I tried today, but can not adjust the carburetor. At idle, gas flows out of the carburetor. And the maximum speed is not getting enough gas. At intermediate speeds is the phenomenon of four strokes.
Finally I ordered a new pump and a carburetor to Himodel.
Thank you for your help.
Jimmymugurel
I tried today, but can not adjust the carburetor. At idle, gas flows out of the carburetor. And the maximum speed is not getting enough gas. At intermediate speeds is the phenomenon of four strokes.
Finally I ordered a new pump and a carburetor to Himodel.
Thank you for your help.
Jimmymugurel
#109
Senior Member

Hi,
Finally I installed a Walbro carburetor. Now the engine runs very well, although it does not look the same.
Until winter comes, I hope to try it and a model airplane in flight.
Mechanical engine is very good, I very much run at very high temperatures without any problems. The problems seem to not like all carburetors.
Regards
Finally I installed a Walbro carburetor. Now the engine runs very well, although it does not look the same.
Until winter comes, I hope to try it and a model airplane in flight.
Mechanical engine is very good, I very much run at very high temperatures without any problems. The problems seem to not like all carburetors.
Regards
#110

I had found that the pump pressure pulse fittings on the pump and engine needed to be larger with a larger hole though them to provide stronger pulses for the pump. Then the engine, carb and pump started to work good for me. I installed a 8/32 fitting into the backplate on the engine and a 8/32 fitting on the pump diaphragm cover. I then used 1/8 inch fuel tubing to connect the engine to the pump.
Now then after a while, I think the regulator diaphragm and the pump diaphragm became softer and stretched out on me, so I replaced them with better Walbro diaphragms. I suspect our USA pump gasoline will affect the diaphragms after a while. I used the Teflon pump diaphragm from a rebuild kit and it worked really good for me. The pump/regulator on the engines uses Walbro carb parts, so fixing it is not a problem. The engine could suddenly start to flood out on you, when that happens, and after cleaning the fuel inlet valve, then you can suspect that the regulator diaphragm has stretched out and isn't shutting the fuel flow off like it should.
Some other fellows had good luck using the Walbro pivot arm on the regulator too, as the stock one is made from a alloy that might be a little too soft, but I haven't had a problem with it. Another fellow found that the spring from the WYL carb (WYJ spring part # 98-3160-7) can help a lot by providing more fuel to the engine too, as it increases the fuel pressure a little bit.
Here is a video of one of my 9cc gas engines on my Escapade low wing plane. I used a OS muffler on the engine to quiet it down a little more.
It actually flies really well and develops good power too. I used a LiFeP04 receiver battery pack and ran the radio off the pack directly and I used a Tech Aero Ultra IBec to regulate the voltage to the CDI unit and also serve as a ignition cutoff switch too. I used a 11x7 prop and regular pump gasoline with Amsoil 2stroke oil (the 100:1 type of oil) at about a 18:1 fuel to oil ratio.
[youtube]http://www.youtube.com/watch?v=0HkMYRiLhPQ[/youtube]
Now then after a while, I think the regulator diaphragm and the pump diaphragm became softer and stretched out on me, so I replaced them with better Walbro diaphragms. I suspect our USA pump gasoline will affect the diaphragms after a while. I used the Teflon pump diaphragm from a rebuild kit and it worked really good for me. The pump/regulator on the engines uses Walbro carb parts, so fixing it is not a problem. The engine could suddenly start to flood out on you, when that happens, and after cleaning the fuel inlet valve, then you can suspect that the regulator diaphragm has stretched out and isn't shutting the fuel flow off like it should.
Some other fellows had good luck using the Walbro pivot arm on the regulator too, as the stock one is made from a alloy that might be a little too soft, but I haven't had a problem with it. Another fellow found that the spring from the WYL carb (WYJ spring part # 98-3160-7) can help a lot by providing more fuel to the engine too, as it increases the fuel pressure a little bit.
Here is a video of one of my 9cc gas engines on my Escapade low wing plane. I used a OS muffler on the engine to quiet it down a little more.
It actually flies really well and develops good power too. I used a LiFeP04 receiver battery pack and ran the radio off the pack directly and I used a Tech Aero Ultra IBec to regulate the voltage to the CDI unit and also serve as a ignition cutoff switch too. I used a 11x7 prop and regular pump gasoline with Amsoil 2stroke oil (the 100:1 type of oil) at about a 18:1 fuel to oil ratio.
[youtube]http://www.youtube.com/watch?v=0HkMYRiLhPQ[/youtube]
#113

Hummm, maybe you did have bad luck with the carb. I remember someone in Australia getting a bad carb on their engine. It had the main needle hole drilled off center, so that one couldn't get the needle to work correctly. I haven't run across that problem yet.
The carb does tend to spit a lot of fuel at low speed. On my engine it looks like it is flooding out or running way to rich at idle or low speed, but the engine will idle for as long as I need it too OK. I have thought about making a little air intake stack for the carb.
But if all else fails, a small venturi Walbro carb works pretty good. But it does make the engine look odd though.
I went a little overboard with my Walbro carb conversion experiment earlier. The Walbro carb spits a lot of fuel too. The main jet is about 4 to 5 mm below the top of the carb and exposed to the airflow going past it. Thus I tried a intake stack they sell for Walbro carbs, I didn't feel like making a smaller one for the engine at the time. But it probably makes the engine look more ugly with the big stack on it.
But to get the Walbro carb to work OK, was when I installed the larger fittings for the pump, and that was what got me to thinking that the OEM pump could benefit with it. Then after modifying my second engine with larger fittings, the OEM carb and pump started working great for me then.
Earlier in another message Michael Chow had stated that the low speed needle is set to about 6 turns out and the high speed about 1.5 turns out. I started using that default setting on my engine and except for tweaking the high speed needle, I haven't felt the need to touch the low speed needle.
Idle speed is with the throttle barrel approximately 1/2 open. And it spits fuel quite a bit.
Now then one other fellow used the slightly softer spring from a WYJ Walbro carb and I think he did something else, but I forget at the moment, that lets him get full throttle movement on his engine. So that idle speed is with the carb barrel almost closed. I haven't tried to duplicate his efforts yet.
My Walbro carb conversion experiment on one of my engines.



Here is a short video of me flying the engine with the Walbro carb conversion on my Ugly Stick
[youtube]http://www.youtube.com/watch?v=mR2N4IM3nCM[/youtube]
The carb does tend to spit a lot of fuel at low speed. On my engine it looks like it is flooding out or running way to rich at idle or low speed, but the engine will idle for as long as I need it too OK. I have thought about making a little air intake stack for the carb.
But if all else fails, a small venturi Walbro carb works pretty good. But it does make the engine look odd though.
I went a little overboard with my Walbro carb conversion experiment earlier. The Walbro carb spits a lot of fuel too. The main jet is about 4 to 5 mm below the top of the carb and exposed to the airflow going past it. Thus I tried a intake stack they sell for Walbro carbs, I didn't feel like making a smaller one for the engine at the time. But it probably makes the engine look more ugly with the big stack on it.
But to get the Walbro carb to work OK, was when I installed the larger fittings for the pump, and that was what got me to thinking that the OEM pump could benefit with it. Then after modifying my second engine with larger fittings, the OEM carb and pump started working great for me then.
Earlier in another message Michael Chow had stated that the low speed needle is set to about 6 turns out and the high speed about 1.5 turns out. I started using that default setting on my engine and except for tweaking the high speed needle, I haven't felt the need to touch the low speed needle.
Idle speed is with the throttle barrel approximately 1/2 open. And it spits fuel quite a bit.
Now then one other fellow used the slightly softer spring from a WYJ Walbro carb and I think he did something else, but I forget at the moment, that lets him get full throttle movement on his engine. So that idle speed is with the carb barrel almost closed. I haven't tried to duplicate his efforts yet.
My Walbro carb conversion experiment on one of my engines.



Here is a short video of me flying the engine with the Walbro carb conversion on my Ugly Stick
[youtube]http://www.youtube.com/watch?v=mR2N4IM3nCM[/youtube]
#115

That is nice to know that the larger bore carb works too. The carb I used is a Walbro WT-298-1 carb and it has a 7.14mm intake venturi bore in it.
I think they were running 8 and 9mm bore carbs on the 15 to 17cc engines. So I figured using a 7mm bore carb would be about right with a 9cc engine.
But if I get around to it, I might try a larger 9mm bore carb like you did and see what happens.
But when the stock carb and pump/regulator was causing my engine to flood out on me, it turned out that the pump and regulator diaphragms were going bad. I replaced them and everything started working OK. The diaphragms looked Ok though, but something was wrong with them. On another engine the diaphragms seemed to stretch out and sag more over time which caused the engine to flood out at low speed and starve for fuel at high speed.
Of course there might have been a microscopic speck of debris inside that got dislodged on me and I didn't see it.
I took a look at one of the regulators on my engine and the lever protrudes a little above the base of the regulator body. But it seems to work OK like that though.
I think they were running 8 and 9mm bore carbs on the 15 to 17cc engines. So I figured using a 7mm bore carb would be about right with a 9cc engine.
But if I get around to it, I might try a larger 9mm bore carb like you did and see what happens.
But when the stock carb and pump/regulator was causing my engine to flood out on me, it turned out that the pump and regulator diaphragms were going bad. I replaced them and everything started working OK. The diaphragms looked Ok though, but something was wrong with them. On another engine the diaphragms seemed to stretch out and sag more over time which caused the engine to flood out at low speed and starve for fuel at high speed.
Of course there might have been a microscopic speck of debris inside that got dislodged on me and I didn't see it.
I took a look at one of the regulators on my engine and the lever protrudes a little above the base of the regulator body. But it seems to work OK like that though.
#116

I have three of the engines in use on planes at present. A Great Planes Big Stick .40, a Great Planes Escapade .40, and a old style .45 size pattern plane too. The Ugly stick has my experiment with a small venturi Walbro carb on the engine. The other two are using the OEM carb parts, albeit I did replace the diaphragms in the pump/regulators and also I used larger 8-32 fittings for the pump and engine too.
















#118
Junior Member
Join Date: Feb 2004
Location: M�xico, D. F.M�xico, D. F., MEXICO
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts

Hi. Good news. I flew today my new RV-4 equipped with this NGH 9cc, in a field above 2,300 over sea level. Excellent capabilities to take off, climbing and good landing without flaps.This engine surelly delivers more than 1 HP. Seems like an .50 IN nitro. I spectted more RPM'S... with an 11 x 6 prop I obtained less than 10,500.Wich prop do you suggest to me?
#119
Junior Member
Join Date: Feb 2004
Location: M�xico, D. F.M�xico, D. F., MEXICO
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts

Hi. Good news. I flew today my new RV-4 equipped with this NGH 9cc, in a field above 2,300 over sea level. Excellent capabilities to take off, climbing and good landing without flaps.
This engine surelly delivers more than 1 HP. Seems like an .50 IN nitro. I spectted more RPM'S... with an 11 x 6 prop I obtained less than 10,500.
Wich prop do you suggest to me?
This engine surelly delivers more than 1 HP. Seems like an .50 IN nitro. I spectted more RPM'S... with an 11 x 6 prop I obtained less than 10,500.
Wich prop do you suggest to me?
#123

My method is (be very careful please):With a help from a buddy a tach. in hand,slightly loosen the sensor screws,run and get the engine to wot. and play very little with sensor.When buddy saw max RPM then there is the place of sensor.I prefer several degrees retard from it to stay in safe side.
#124
Junior Member
Join Date: Feb 2004
Location: M�xico, D. F.M�xico, D. F., MEXICO
Posts: 25
Likes: 0
Received 0 Likes
on
0 Posts

Thanks Turk1 for your advice and instructions. I'll do it. Yesterday a flew and , good flights but this engine sudenlly appears to turn off. Al idle, it doesn't run constantly: the RPM's goes from 2700 to 3200 every 2 seconds.... This is TIMMING to correct, isn't it?
Thanks Turk1
Thanks Turk1
#125

ORIGINAL: bgoyos
Thanks Turk1 for your advice and instructions. I'll do it. Yesterday a flew and , good flights but this engine sudenlly appears to turn off. Al idle, it doesn't run constantly: the RPM's goes from 2700 to 3200 every 2 seconds.... This is TIMMING to correct, isn't it?
Thanks Turk1
Thanks Turk1 for your advice and instructions. I'll do it. Yesterday a flew and , good flights but this engine sudenlly appears to turn off. Al idle, it doesn't run constantly: the RPM's goes from 2700 to 3200 every 2 seconds.... This is TIMMING to correct, isn't it?
Thanks Turk1