Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: JinMachine on May 13, 2020, 11:59:33 pm
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Great news Raphael :D
Sounds perfect now!
Thank you for the great videos, i'm sure they will help others if they have the same issues.
Best wishes
Ade
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Hi Raphael, It is great to see your little engine running so well!
Well done and good on you Ade for helping Raphael get it dialed in.
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Looks like it’s turning into a great little runner ;D
Has anyone else received theirs yet?
Matt.
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So glad to see that this was just a minor adjustment issue ..... once all the adjustments were properly identified and understood.
Congratulations Raphael, and well done Ade!!!!
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Bonjour Ade,
I have followed your advice and now my little engine runs perfectly. Thank you again for your great help ;)
https://youtu.be/eWyFKhBtrgE
Sorry again for the poor quality of this video.
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Bonjour Raphael,
Not quite,
1. First we set the main jet, this is the silver one by the fuel inlet pipe (ignore the other jet for a minute). Open the throttle fully and adjust this jet until the engine runs at full throttle.
2. Then reduce the throttle until the engine starts to run badly, this is the time to gradually adjust the slow speed needle (the gold one in the centre of the throttle arm) until the engine runs nicely.
3. Repeat step 2 until you can get right down to a fast idle speed.
I have a feeling this engine will overspeed at full throttle with no load, if this is true then keep adjusting period very short, we only want to find a baseline setting for now.
For this type of carb in an RC engine the main jet setting is critical to provide full power and keep the engine rich enough not to overheat, but with this little engine we only need a basic setting of the main jet for now so the slow speed needle can do its job.
I hope this helps
Ade
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Bonjour ,
MERCI ADE !
Thanks to your useful information, I have discovered this second needle and it was tight. I am sure it will run correctly after its setting. And you will also help a lot of other owners ;)
https://youtu.be/DqWvDZ9m-y0
To summarize, to set this engine could you confirm that I should :
- open full throttle and try to start with the long "silver" needle 1/4 turn and simultaneously open the little "golden" needle 1/4 turn (throttle side).
- If the engines runs fast, slow down the throttle and adjust the little "golden" needle.
Am I right with this procedure ?
Jin does not mention that there are two needles to adjust:
https://www.youtube.com/watch?v=skSME3glIiE
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Bonjour Raphael,
Quick question, the carb looks like it is based on an RC model engine carb, these usually have two mixture adjusting screws. The one you are moving is the main jet, this usually controls 2/3 to wide open throttle and then there is a second screw (the idle adjust) which is usually situated in the centre of the throttle arm. If you see an adjuster there then i think maybe the low throttle is too rich and to compensate for this you screw in the main jet, so now the main jet meters the fuel at low throttle, BUT when you open the throttle the engine dies because the main jet is not supplying enough fuel.
May i suggest, if you see a low speed adjustment screw, open the throttle wide open, crank the engine and at the same time open the main jet until the engine fires/runs (the high speed adjustment should be done first) once you get the engine to run at full throttle then gradually close the throttle and adjust the low speed needle until you get the best low speed running.
I hope this helps, i'm only guessing based on experience with RC aeroplane engines.
Best wishes
Ade
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It is definitely running better Raphael.
As you run it more, I think it will only get better.
Thanks for all of the videos of your trials (and tribulations).
Regards,
Charlie
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Bonjour,
This video confirms that, even if the compression is very weak, although it improves a little with the rise in temperature of the engine, everything is in the VERY precise adjustment of the carburetion. I touched the small secondary screw on the side of the carburetor to close the throttle a little. It is a millimeter or less.
https://youtu.be/ecpM298SChU
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Bonjour Ade,
Good idea ! I had already added a drop of oil in the gas but will add a little bit more,because, as noticed by Tom, there is not too much smoke.
Besides this, please note that this engine is a 1,6 cm3 and not a 2,6 cm3, Jin has to progress in arithmetic calculation ;D
There is a secondary oil needle on the other side of the engine carburetor that needs to be fine-tuned! When working, make sure that there is at least 2/3 of the oil in the fuel tank. For small engines, it needs enough liquid level to supply oil normally.
Before the first engine is shipped, we have been debugged to reach normal work before we can ship it.Jin
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Bonjour Ade,
Good idea ! I had already added a drop of oil in the gas but will add a little bit more,because, as noticed by Tom, there is not too much smoke.
Besides this, please note that this engine is a 1,6 cm3 and not a 2,6 cm3, Jin has to progress in arithmetic calculation ;D
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Bonjour Raphael,
For my 2 cents i would say the low compression leads to this kind of poor running and extreme mixture sensitivity. It is improving as you run it so i guess things are bedding in and compression is rising, however it sounds tight and squeaky by the end of video number 2 like it is lacking lubricant. If it were mine i would oil every moving part excessively during the bedding in period and insert a few drops of oil into the carb before each start to boost compression and lubrication. Hopefully this way will allow the process of bedding in to continue as you run it allowing internal friction to reduce and compression to rise until it runs acceptably.
Kind regards
Ade
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Bonjour Tom,
He is the instructions manual, It does not help a lot. Besides this, I did not touch anything about compressionbecause I have no knowledge on this type of engines and no appropriate control tools... To you opinion, the miing is poor, I will try to open a little bit mor the mixing needle.
https://youtu.be/skSME3glIiE
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Hi Raphael, ..I only have a good running, sorted-out M90 engine & sorry you're having new engine running problems,
as multiple issues could exist .Your engine running videos are very interesting & i Didn't notice any excessive dark exhaust smoke which would indicate an over rich fuel condition, so maybe it's too lean...How did you fix the initial "no compression" symptoms ? assuming you now have good "snappy" flywheel compression flip feel & good, normal carb intake suction since any basic engine issues including intermittent ignition cut-out problems could make carburator tuning
a nightmare. I keep an intentional small sparkplug wire connection arc gap visible to instantly monitor ignition issues during engine running problems... As your M12 carburator is probably a lot more complex than the previous M90 engine series simple fuel mixer needle valve, Does your instruction manual include clear step by step tuning proceedure illustrations, sometimes using a tachometer & fuel line "pinch" tests to help you achieve organized, high speed, low speed, stumble free rpm transition & idle speed stops tuning adjustments ? Hope you get all sorted out & share with us...Regards,...tom.
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Bonjour;
Little progress but not success, it finally starts... then stops alone and I can not accelerate, to your opinion, mixing air / gas too rich or too poor ?
https://youtu.be/atrMaX_Hbbs
https://youtu.be/lse8oG1qkwQ
I feel disapointed... :(
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Well, i sent Jin a PM. Now down to waiting to hear back from him. Hopefully it will be soon.
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Hi, first of all, every engine will be shipped after careful debugging to reach the normal start. The carburetor has been debugged to the best working state. Therefore, it is recommended not to make too large adjustments!
Without compression, there may be foreign objects at the valve, which prevents the valve from closing properly. You can unscrew the four screws on the cylinder head. Check the valve. (This kind of small valve is only 6MM).
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Received my M12 today as well. Excitement quickly turned to resignation. The original switch was bad, no flow. Replaced it with a new 6A 125v switch, still no fire. Base voltage through new switch, only way to check module is disassembly. Also, noticed the pickup is rather loose in its housing, letting it move easily and the supplied screw are barely long enough to engage threads as it is. So, I have to wait on a module, source longer screws, shim the pickup so that it remains in range of the magnet, and then maybe I can fire mine up. What, figure 3 weeks? Or maybe a month and a week...😝😤
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Bonjour Ade,
Yes, there is a little clearance and when I put my finger in front of the inlet or the exhaut, I feel nothing, this is why I I suspect a piston ring problem which will force me to dismantle the whole engine with the strong risk of unregulating it ...
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So sorry to hear this Raphael.
Let us know if you get it running.
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Hi Raphael,
I guess you checked there is some clearence between the rocker arm and valve when the valve is closed? May i suggest putting your finger over the inlet and then exhaust while turning the engine, if you feel pressure on your finger and a little compression then you have identified a faulty valve. If you have a valve issue and clearence is present then it is usually a particle stuck between the valve and its seat. Sometimes flicking the valve open with your finger so it snaps shut will clear this or maybe flood the engine with fuel and spin it with the drill adaptor.
Hope this helps
Ade
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Bonjour,
I have received my M12 #2 today and big disappointment, it does not work, it has no compression. At this moment, I don't know what to do to solve this problem and Jin is far away ...
https://www.youtube.com/watch?v=fMq_bAuOxQs
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Not sure how to track it, but I will let you know if I receive mine.
If you paid with PayPal, you can go tonthebitem in your account. Jin has updated the invoice with a tracking number.
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Bonjour,
I have paid my M12 with Payal and Jin has given me a package number I can follow it with : https://www.17track.net/fr
My first package has been sent bac to Jin by the Chineese authorities for Security reasons... ???
Wait and see for the second try currently flying over the ocean...
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Not sure how to track it, but I will let you know if I receive mine.
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So, anyone else tracking their M12? Mine has been sitting in Chicago customs, for over a week now. Starting to wonder if som custom agent decided they wanted one.
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Very nice
Its small footprint size makes it quite nice to collect.
Keep up the good work. Al
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I'm guessing the inspiration for this model was the single cylinder diesel engines by Changchai and other makers.
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Bonjour,
Jin has just informed me that my package is posted... I am looking for receiving it !!!
Generally, I have to wait for several weeks... Lets's see who will be the first happy owner... ;)
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Now i might be in trouble .
The wife likes it a lot
I will be in the same kind of trouble when Mrs RedRyder sees it!
Wish I had that kind of "Trouble" around my house!
I'm sorry I shouldn't make so many "Trouble" for you. Jin
No worries, Jin.
We like this kind of trouble!
Gil
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Now i might be in trouble .
The wife likes it a lot
I will be in the same kind of trouble when Mrs RedRyder sees it!
Wish I had that kind of "Trouble" around my house!
I'm sorry I shouldn't make so many "Trouble" for you. Jin
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Now i might be in trouble .
The wife likes it a lot
I will be in the same kind of trouble when Mrs RedRyder sees it!
Wish I had that kind of "Trouble" around my house!
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Now i might be in trouble .
The wife likes it a lot
I will be in the same kind of trouble when Mrs RedRyder sees it!
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Now i might be in trouble .
The wife likes it a lot
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Very nice, engine, Jin...!!!
Looks great. Very nicely presented and runs great!
Gil
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Nice work Jin, thanks for the video 8) Wish I could buy one, maybe one day...
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Nice engine Jin
Is the wooden base the same on the picture or the M92 engine ?
Thank's for answer.
Alan
I'm sorry this is a small wooden seat for the engine. Jin
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Bonjour,
My M91 was #3, I wonder which number will have my M12 ;)
Yes, the first 30 units are numbered.
Jin
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nice looking engine, runs well & I really like the solid base.....very handsome.
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Bonjour,
My M91 was #3, I wonder which number will have my M12 ;)
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Nice engine Jin
Is the wooden base the same on the picture or the M92 engine ?
Thank's for answer.
Alan
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What a little gem! Lovely job Jin :D
Best wishes
Ade
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We have completed the M12 engine. Now we start to arrange the delivery. This is the final picture and video. Jin
[attach=1][attach=2][attach=3]
http://www.microcosm-engine.com/m12-mini-engine-subscription-plan-p-332.html#.XrzJ3tZGL1Z
https://youtu.be/jApWJ8gKWIU