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Old Nov 02, 2012, 04:26 AM
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brace's Avatar
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Don't feel too bad if they have done very few changes, the work which has been done on the thread mostly involves only minor stuff. For what it is worth the cleaning up and replacing of gaskets/diaphragms on the pump/regulator is SOP for myself on all chinese engines and if they have a reed valve then that too gets inspected and cleaned up before the engine goes on the test stand.
most of the work has been done by Earlwb and I must thank him for his efforts as it has encouraged me to go on and make the motor work. Still a way to go but I am confident enough to now own three of these
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Old Nov 02, 2012, 07:50 AM
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I don't think they did anything to the engines, in China the engines all seem to be working fine, no problems. They do test run the engines along with the carbs and pump/regulators too. So maybe the engines work fine for most people. I would suggest bench test running the engine to see how it goes first. if it works for you OK then great, but if you have problems we detailed what we did to correct the problems in this thread.

One thing to note is that it appears that very few people have had problems with the engines. They seem to have sold quite a few of them so far too. If lots of people were having problems there would have been a lot more messages posted in this thread about it. But people haven't been coming in and stating they had issues.
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Old Nov 06, 2012, 03:11 AM
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Just tried a 12 x 6 master airscrew K Series prop. @9800 rpm, nearly pulled the stand over. Unfortunately I did not check the temp so I don't know if it was getting a little too warm.
Back home now so will finish putting stick together and go flying next week.
Glenn
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Old Nov 06, 2012, 07:59 AM
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I haven't bought one because of all the issues seen here? Quite honestly I thought it was kind of a "work in progress", but I've just checked in here on occasion. Haven't been following it closely?

If these things are pretty much ready to go I may spring for one. I don't mind going through it to make sure it's clean, then doing a little tinkering to get the needles right, but beyond that my interest level drops off quickly. Am I understanding correctly this is where it's at now?

If necessary, would somebody mind doing a short "recap" on what one might have to do to see one of these successfully launched (assuming prior gas experience)?

Any thrust estimates? The 12x6 MA prop at close to 10k? Is that in the range of what I might expect? Target rpm to prop for, regarding good performance vs. reliability? 20:1 oil, correct?

Earl, I see you're running a Mac's header on one of yours. What was it for originally? Bolt on, or was it modded? Thinking side mount. That header would work perfectly.

Thanks, -Al
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Old Nov 06, 2012, 11:00 AM
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United States, CA, San Diego
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Quote:
Originally Posted by Chophop View Post
BTW, I dropped by to ask what size plane can use this motor ?
This plane may be a little pricey but it sure is sexy and would work well.



http://www.horizonhobby.com/products...-72-arf-SEA144

I looked through the manual and it looks like there is plenty of room on the firewall to mount the pump and plenty of room in the fuse for the ignition. Especially if you use a smaller fuel tank. The cowl gets pretty "swiss cheesed" to mount a two-stroke though.

Mike
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Old Nov 06, 2012, 11:48 AM
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Quote:
Originally Posted by ahicks View Post
I haven't bought one because of all the issues seen here? Quite honestly I thought it was kind of a "work in progress", but I've just checked in here on occasion. Haven't been following it closely?

If these things are pretty much ready to go I may spring for one. I don't mind going through it to make sure it's clean, then doing a little tinkering to get the needles right, but beyond that my interest level drops off quickly. Am I understanding correctly this is where it's at now?

If necessary, would somebody mind doing a short "recap" on what one might have to do to see one of these successfully launched (assuming prior gas experience)?

Any thrust estimates? The 12x6 MA prop at close to 10k? Is that in the range of what I might expect? Target rpm to prop for, regarding good performance vs. reliability? 20:1 oil, correct?

Earl, I see you're running a Mac's header on one of yours. What was it for originally? Bolt on, or was it modded? Thinking side mount. That header would work perfectly.

Thanks, -Al
Yeah the NGH engine has the same muffler bolt spacing as many other .45, .46, 52, and .55 engines have. The Mac's muffler is one for a OS 55AX and it bolts right on. I am running a OS .46AX Power Box muffler on another engine, and the third engine is using a Tower Hobbies .46 muffler.

I posted some pics and RPM measurements I got with some different propellers recently with one of my engines. It is back a few posts here in this thread. You can use the prop power calculator spreadsheet that Pe Reivers came up with from mhis website site at MVVS-NL.com. It will show you some typical thrust and speed results.

My Escapade .40 with a NGH 9cc engine was clocked at about 65 mph in the air using a Doppler Shift speed measurement program. it uses a 11x7 Master Airscrew Prop on it.

Through the efforts of several other people and myself, we came up with this list of things to do or check.

1. The motor may not be a plug and play engine right out from the box, you may need to do some work and buy some more items.

2. First is I would take off the back plate of the motor and replace the threaded pressure nipple with a larger one. 8/32 fitting from Dubro seems to be the popular one and this will require drilling and re-tapping. I also replaced the pump fuel fitting with a larger 8/32 fitting too.

3. The pump/regulator should really be pulled apart and serviced with a Walbro K20-WAT kit, this will replace the diaphragms, gaskets, metering lever and plunger needle. I would also have a look at the faces of the unit where the gaskets seal on and see if they are smooth. If not then smooth them off by putting some cutting paste on a sheet of glass and run the face over it in a gentle figure eight motion to bring the surface smooth and level. I used a fine stone at first and while this worked it created a slight curve in the face which I later had to remove. The new gasket and diaphragm will handle the newer fuels and not get out of shape quickly. I like using the white Teflon pump diaphragm but trhe blue diaphragm works fairly well too. The Black diapghragm also works good in comparison to the OEM rubber parts. You may be able to forgo the smoothing operation, it depends on how well the pump/regulator works for you and how much it leaks or seeps when the engine is running.

4. If you are really into servicing the pump/regulator then you can also replace the metering spring with a Walbro WYJ 98-3160-7. The spring is a little more short and increases the fuel pressure to the engine. If you mount the pump/regulator really close to the engine, you may not needed it though.

5. Some people have used 1/8th Viton tubing for the pulse line to minimise loss of pulse to the pump/regulator. I have seen some use a brass tube with tygon at each end to do the same thing, not a bad idea but you would want the tubing to be barbed. I had good luck just using 1/8 inch Tygon tubing though.

6. When putting the motor on the test stand, or plane, have the pump/regulator on some sort of foam mount to absorb vibration. It has to be positioned as close as you can to the carb, allowing for the exhaust pipe, 80mm is the recommended maximum distance.

7. Fuel tank can be where ever you find space and height is not an issue.

8. When fitting the prop, be sure the collar which has the earth magnet for the hall sensor is in the correct position. It can be rotated and fitted back in place 180 degrees out. I am sure all of us have made the mistake but it is easy to check, rotate engine until tdc and sensor will be near the magnet.

9. Make sure all your fuel connections are air tight and secure.

10. Fuel mix is 20:1 don’t even think about 25:1. I also use a really good oil such as Amsoil Saber Pro 100:1 or Stihl Ultra oils in my engines.

11. Without the new spring on the pump/regulator my needle settings are LSN a touch more than 2 1/2 HSN just under 1. When you first start it I would put the LSN at 3 and the HSN at 1 . Depending on your mods, the standard LSN needle setting is six turns out and the high speed is 1 and half turns out. Idle is typically 1/2 open of the carb. But with the mods you may have it closer to being closed though.

12. Be sure you are only supplying the correct voltage to the ignition unit 4.8v. The CDI using is rated for 6.0v maximum and they really mean it. A five cell Nicad or NMH pack exceeds 6.0v when fully charged as do LiPo packs or LiFe packs. Anyway a 4 cell 4.8v battery pack works quite well any extra voltage won't gain anything at all.

13. Before starting with the ignition off rock the prop back and forth to pump fuel up to the carb. Start the motor with about 1/2 of the barrel open. If it does not start straight away you may need to open it more to get more air into the motor. Starter motor required. Unlike the glow engines idle speed is around 1.2 open on the throttle barrel. The engine does spit fuel and it isn't running too rich like that. I have idled mine for quite a while like that and they didn't load up appreciably either.

14. Adjust your needles to best setting. I have so far with an engine that is still running in, achieved 2500 to 10500 rpm with a 10.5x6 APC prop.. Note I myself (earlwb) have been using 11x7 Master Airscrew props for the engines, but others are using different props.

15. Motor runs nicely but does sputter a bit and definitely spits fuel out as the carb is very basic and only just does the job. Work in progress with improving the performance.

16. Some people had problems trying to run it inverted and that may be the carburetor design. So it doesn't like that so far.

On my engines I wound up with idle speed being with the carb barrel about 1/2 open. So your results could vary on that.

The OEM rubber diaphragms in the pump/regulator may work much better using gasolines outside of the USA. Here in the USA they use ethanol in the fuel along with a number of other unpronounceable chemicals too. Here in the USA the SEF or Tru-Fuel premix gasolines don't deteriorate the rubber parts as fast and it may not need replacing then. The Chinese didn't have our USA gasolines to use in the engines so they wouldn't have likely encountered the problem. With USA pump gasoline the rubber parts get soft and stretch out and thus quit working on one.
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Last edited by earlwb; Nov 06, 2012 at 11:51 AM. Reason: Corrections and forgot to add something
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Old Nov 06, 2012, 12:09 PM
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great read and work earlwb
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Old Nov 06, 2012, 05:59 PM
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Hello Earlwb. I have many problems with this engine and now you are helping me a lot. Thank you.

I have a basic question. There are three needles engine. The HSN ok. But the other two needles do not work well. What is the correct LSN?

The other needle should be with how many turns?

Augusto.
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Old Nov 06, 2012, 08:20 PM
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For myself I am using the low speed needle set to about 6 turns out and the high speed needle set to about 1 and a half turns out. There is only the low speed and high speed needle adjustments on the engine. But it is interesting about that third set screw below the main needle. Honestly, I do not know what it is for. I have never touched it.
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Old Nov 06, 2012, 10:19 PM
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Pleasant Valley Modelport
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Great looking plane, but I am most interested in one more like the Great Planes Sequence, and NO PINK ! Please, quit invading our masculinity with this preposterous insult.

http://www3.towerhobbies.com/cgi-bin...?&I=LXWWM1&P=0

Quote:
Originally Posted by CryHavoc View Post
This plane may be a little pricey but it sure is sexy and would work well.



http://www.horizonhobby.com/products...-72-arf-SEA144

I looked through the manual and it looks like there is plenty of room on the firewall to mount the pump and plenty of room in the fuse for the ignition. Especially if you use a smaller fuel tank. The cowl gets pretty "swiss cheesed" to mount a two-stroke though.

Mike
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Old Nov 07, 2012, 12:55 AM
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brace's Avatar
Australia, NSW, Ashby
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Needle settings will vary considerably depending on what work you have done on the carb, the quality of the needle and taper (seems to be some variance) etc. My low speed needle is set at about 2 1/2.
Had a go with a piece of tube for a velocity stack, had to change the needle settings a bit and to be honest other than less spitting I am not all that convinced of any significant change. Going to try another design and see if I can improve the carb performance, just waiting on some material but it will be very simple
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Old Nov 07, 2012, 03:38 AM
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United States, CA, San Diego
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Quote:
Originally Posted by Chophop View Post
Great looking plane, but I am most interested in one more like the Great Planes Sequence, and NO PINK ! Please, quit invading our masculinity with this preposterous insult.

http://www3.towerhobbies.com/cgi-bin...?&I=LXWWM1&P=0
The Phoenix Models Jupiter is similar to that Sequence.

http://www.towerhobbies.com/products/pmm/pmma0260.html

I'm not entirely sure these engines are best suited for these types of planes though. Not only because of the extra weight and lower power output but the lack of a steady low throttle rpm and questionable reliability will hamper any precision aerobatics and you can forget 3D altogether. That leaves sport planes and scales with lots of wing area.

Mike
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Old Nov 07, 2012, 03:46 AM
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The mysterious 3rd needle is to adjust spray bar length(posiiton of spraybar mouth )So no need to play unless feel unproper placing of spraybar mouth.
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Old Nov 07, 2012, 09:22 AM
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Quote:
Originally Posted by earlwb View Post
For myself I am using the low speed needle set to about 6 turns out and the high speed needle set to about 1 and a half turns out. There is only the low speed and high speed needle adjustments on the engine. But it is interesting about that third set screw below the main needle. Honestly, I do not know what it is for. I have never touched it.
The problem is that I changed this third screw. Nothing is working now, even after doing all the step by steps you indicated.

The LSN is inside the throttle arm?

Augusto.
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Old Nov 07, 2012, 10:15 AM
A few Models is not enough Hon
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Australia, WA, Noranda
Joined Mar 2007
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Quote:
Originally Posted by augustomoura View Post
The problem is that I changed this third screw. Nothing is working now, even after doing all the step by steps you indicated.

Augusto.
I have 2 of these engines and both have the 3rd screw set all the way out from the factory
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