Artikel : How to set / tune glow engine

[Wind Raider]

How to set/tune your engine

Too often, I see newcomers to our hobby ask online how many turns do I set my needle valves, or I messed up the factory setting, how do I setup my low end needle so I can start my engine? Here are some great tips to make you an expert engine tuner.

How to setup the needles so you can get your engine started:

Start by opening the high end needle about 4 turns from fully closed. This is just a starting point to ensure the high end needle valve isn't restricting fuel to the carb so you can adjust the low end needle setting.

The low end is easily set to a good starting point with the following procedure:

Close low end needle valve completely.

Install a clean piece of fuel tubing into carb fitting, make sure it is long enough for you to blow into it with your mouth.

Open carb to 1/5 open from closed position

Blow into fuel tubing while slowly opening up the low end needle valve. Stop turning low needle valve when you first feel air blowing into carb from your mouth or hear the sound of air blowing into carb. The flow should be restrictive and very small. We only want a small amount of fuel to flow (air to flow) at 1/5 throttle opening. This low end needle setting will get your engine running and may require further adjustment. THis is just a ball park setting.

Now close high end needle valve and open carb to full throttle. Blow in fuel tubing and simulataneously open high end needle until you have FREE FLOW of air into carb. You should not experience as much resistance to airpressure as you did on the low end. Your needle valve should be open between 2-5 turns (it all depends on the carb folks).

This procedure gurantees you don't have a blocked carb or closed needle settings for low and high. This will get you in the ballpark which then will require you to fine tune your low end and high end for best performance--highly recommend the pinch test .

Pinch test procedure:

First start engine this way:
Prime engine by opening up throttle to full and blocking exhaust with finger. With blocked exhaust, rotate engine until fuel just enter's the carb-watch fuel line to see fuel displacing the air in the fuel line.

Remember the following rules about needles:

1. Low end needle affects the mixture below 1/2 throttle for most engines. Use it to adjust the idle and the transition from idle to full throtttle.
2. High end needle affects mixture above 1/2 throttle. Adjust it so engine is running 300-400 rpm shy of max lean rpm at wide open throttle.


Reduce throttle from full to about 1/5 throttle opening. Apply glow ignitor and rotate engine (hopefully w/ starter) counterclockwise (for 99% of all engines out there) until engine starts. When engine starts, move throttle to 1/2 throttle and then remove glow driver.

If engine won't start, try more throttle until it does. If engine will only start above 1/2 throttle, it means your initial low end needle setting was too lean. Richen it about an 1/8th of a turn until the engine starts at a low throttle (1/5 throttle) setting.


If engine will not advance to 1/2 throttle w/ glow driver is on then leave at 1/5 throttle with glow driver until engine is warmed up-about 2 minutes should do the trick.

Advance throttle again to 1/2 throttle slowly. If engine dies then your low end needle is probabably too lean. Richen by 1/10 increments.

Once you can get your engine running at 1/2 throttle then its time to remove the glow driver/ignitor. With ignitor removed, advance throttle to full throttle. Chances are your engine will be too rich and may even quit. If so, briefly pinch and release fuel line as you advance to full throttle to verify the mixture is too rich. If it is too rich, then in small increments lean it out until it will run at full throttle without quitting. This does not mean the high end mixture needle is set. This is just a starting point to ensure your engine is running at wide open throttle (WOT) so you can make the proper adjustments.

With engine running at full throttle, slowly and carefully lean the high end needle valve until the engine is spinning at its max rpm. This can easily be determined by sound alone-no tach needed. This is where engine is producing most power but the mixture setting will cause the engine to run too hot and overheat. So, as a safety feature, always richen the mixture about 300 rpm shy of max lean rpm. Verify this by briefly pinching and releasing the fuel line to the carb. If the pinch test causes the engine to speed up and back down, then you have correctly set your high end needle setting. If engine doesn't speed up much or dies then you are still to lean and need to riche the mixture slightly until it passes the pinch test.

You are almost there. With high end needle setting set about 300 rpm rich of max lean rpm, recheck idle and transition. Let engine idle for 30-60 seconds and then snap throttle to WOT. If engine hestitates in the transition, fine tune mixture so that the transition is snappy and idle is reliable. I personally like a lean idle mixture so I can idle for long periods without fuel pooling up in the crankcase which causes stumbles when transitioning to full throtttle. You can also use the pinch test when the engine is idleing. Pinch and hold fuel line with engine at a fast idle. Engine should speed up and die about 4 seconds. If it takes longer, your low end needle is too rich, if it takes less time or if your engine dies instantly, you are to lean and need to richen your low end needle.

Once low end needle is set, you will probably never have to adjust it again. However, your high end needle should be checked before every flight by doing the pinch test at WOT to verify the mixture is slightly rich. This 5 second test and adjustment, if necessary, will gurantee you a reliablie engine that will last a long time. Our carbs do not adjust for changes in temperature, humidity, barometric pressure, etc... and a small change of 5 degrees in temp can cause a properly tuned carb to be out of tune and possibly too lean (or too rich depending on whether it gets hot or cold outside).

Hope this essay helps the newcomers to our hobby and prevents them from becoming one of the set it and forget it crowds that do not benefit from optimum tuning for the best engine performance and longevity out of an engine.

link : http://www.rcgroups.com/forums/showthread.php?t=205602

[Wind Raider]

Terjemahan bebas / ringkasan ( mohon dikoreksi kalau keliru )

Seringkali orang bertanya bagaimana cara menyetel carburator atau setelan carburator telah digeser2 sehingga mesin jadi tidak normal .
Berikut ini adalah cara menyetelnya kembali :

A. Bagaimana cara mensetup jarum sehingga engine bisa hidup :

1. Putar jarum HIGH END agar sepenuhnya menutup . Kemudian buka jarum high end sekitar 4 putaran dari posisi sepenuhnya tertutup. Ini hanyalah titik awal untuk memastikan katup high end jarum tidak menghalangi fuel ke karburator sehingga Anda dapat menyesuaikan pengaturan jarum LOW END .

2. Putar dengan obeng jarum LOW END sampai sepenuhnya menutup .

3. Lepaskan selang fuel pada carburator . Pasang selang lain yang bersih ke tempat masuk fuel pada carburator , pastikan panjangnya cukup untuk meniup angin dengan mulut Anda .

4. Buka lubang Carb untuk 1/5 buka dari posisi tertutup .

5. Tiuplah selang sambil perlahan membuka katup jarum LOW END . Hentikan putaran jarum LOW END saat pertama kali merasakan udara masuk ( desisan angin ) ke karburator . Aliran udara harus sedikit saja . Kita hanya ingin sedikit fuel ( udara yg Anda tiup ) yang mengalir pada pembukaan throttle 1/5.

6. Sekarang putar jarum HIGH END sampai posisi menutup dan buka lubang Carb sepenuhnya ( Wide Open Throttle ) . Tiuplah selang sambil membuka jarum HIGH END sampai udara bebas masuk ke karburator . Posisi jarum HIGH END harus terbuka antara 2-5 kali putaran ( tergantung pada jenis karburatornya ).
Prosedur ini untuk memastikan Karburator tidak terblokir untuk settingan High End dan LOW END .
Sekarang waktunya cubit2an eh pinch test , maksudnya ..



B . Prosedur Pinch Test :

1. Pasang kembali selang fuel ( yang kita lepaskan tadi ) ke karburator .

2. Prime engine dengan membuka throttle penuh dan tutup lubang karburator dengan jari . Putar baling2 sampai fuel pas masuk ke karburator . ( prosedur ini seperti waktu kita menyalakan engine )

catatan :
Jarum LOW END mempengaruhi campuran di bawah 1/2 throttle . Gunakan untuk mengatur idle dan transisi dari idle ke full throtttle
Jarum HIGH END mempengaruhi campuran di atas 1/2 throttle. Digunakan untuk menyetel engine untuk mendapat kecepatan maksimum pada waktu full throttle .

3. Set throttle pada posisi 1/5 throttle. Pasang pemanas busi ( glow driver ) ; putar baling 2 dengan stater sampai mesin hidup . Ketika mesin sudah hidup , pindahkan gas ke 1/2 throttle ; kemudian cabut glow drivernya .

catatan:
Jika mesin tidak menyala , lakukan kembali langkah 1 dengan menaikkan throttle sedikit ( diatas 1/5 throttle ) . Jika engine hanya akan menyala di atas 1/2 throttle, itu berarti setelan LOW END terlalu 'LEAN'. Perkaya ( 'enrichen' ) lagi sekitar 1/8 putaran sampai engine bisa hidup pada 1/5 throttle.
Jika engine mati begitu glow driver dicabut , pasang glow driver , hidupkan kembali dengan 1/5 throttle ; panaskan engine selama 2 menit . Kemudian pelan2 naikkan gas sampai 1/2 throttle .
Jika engine mesin mati maka jarum LOW END Anda mungkin terlalu 'LEAN'. Perkaya ( "Enrichen" ) lagi sekitar 1/10 putaran .

4. Nah , setelah engine bisa tetap hidup dengan 1/2 throttle , cabutlah glow drivernya . Majukan throttle ke full throttle. Ada kemungkinannya campuran terlalu 'rich ' kaya dan bahkan engine mungkin berhenti berputar .
Jika demikian, segara jepit dan lepas ( sebentar saja lho , istilahnya briefly pinch and release ) selang fuel untuk mengetahui apakah campuran terlalu 'RICH'.
Jika terlalu 'RICH', maka sedikit demi sedikit kecilkan fuel masuk dengan memutar jarum HIGH END , sehingga engine tetap hidup pada full throttle .




C. Setelan Akhir HIGH END dan LOW END

1. Dengan engine berjalan pada posisi FULL THROTTLE , perlahan-lahan setel jarum HIGH END agar engine berputar pada rpm maksimal . Di sinilah engine ini menghasilkan daya paling bertenaga tetapi pengaturan campuran akan menyebabkan engine terlalu panas dan akan overheat . Jadi, agar engine awet , setel jarum HIGH END agar putaran engine turun sekitar 300 rpm dari RPM MAX .Untuk memverifikasi , pijit dan lepas selang fuel . Jika putaran engine jadi tambah cepat kemudian kembali turun , maka Anda settingan HIGH END sudah benar . Jika tidak demikian atau bahkan engine mati , maka setelan masih terlalu 'LEAN' dan harus diperkaya ( RICHEN ) sampai test 'Pinch and Release ) terpenuhi .

2. Check dan recheck idle dan transisi.

3. Biarkan mesin idle selama 30-60 detik dan kemudian gerakkan ke full throttle . Jika perpindahan dari idle ke full throttle tidak mulus , maka setel mixture / jarum Low End agar perpindahannya jadi mulus .

Anda juga bisa mengetes engine waktu idle , dengan cara menjepit selang fuel , tahan jangan dilepas ( Pinch and Hold ) .
Putaran engine seharusnya bertambah cepat dan mati 4 detik kemudian .
Jika terlalu lama matinya berarti settingan jarum LOW END terlalu 'RICH' .
Jika waktunya kurang dari 4 detik atau segera mati , itu tandanya terlalu "LEAN' .
Setel kembali jarum LOW END sampai test "Pinch and HOLD" terpenuhi .

Begitu jarum LOW END selesai diatur, jangan diutak atik lagi . Setelan HIGH END masih boleh diubah2 untuk penyesuaian dilapangan .

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
catatan istilah :
fuel = bahan bakar engine
mixture = percampuran udara dan fuel .
rich mixture = fuel kebanyakan
lean mixture = fuel terlalu sedikit .
enrichen = putar jarum kekiri ( anticlockwise )
lean out = putar jarum kekanan ( clockwise )
jarum HIGH END = setelan fuel masuk yang bisa diputar dengan jari
jarum LOW END = setelan yg terletak pada pivot servo , hanya bisa diputar dengan obeng .

[jong66]

Makasih om Wind..artikel ini bener2 bermanfaat buat kita2 nubi di glow engine, pas bgt ni krn hampir tiap mau terbang msti menghadapi kendala settingan, terutama utk glow yg ukrn kecil/25 ke bawah..

NB: Iya nih..brhubung bnyk yg bhs Inggrisnya grothal grathul spt sy(Jw, = kedodoran ) dimohon utk rekan2 yg 'English'nya sdh advance bisa bantu terjemahinnya..

[joko]

Oalah...ngeliat judulnya di "new Post", menarik nih...
Tinggal caplok! Jebule musti di cas, cis, cus dulu....

[christoffel]

posting yg no 2 itu buat engine nitro rc-car suhu.
waktu break-in dia main di idle.
kalau untuk aircraft agak beda ...
kalau break-in nya di idle terus engine nya nggak panas2 ...
kalau yg pake ABC atau ABL type bisa lewat engine nya ...

[Wind Raider]

Ohhh begitu ya ... .
Postingan ke2 karena utk rc car engine , jadi saya hapus biar tidak membingungkan ..
Thanks Om Christ atas koreksinya .

[Wind Raider]

:mtp
Makasih om Wind..artikel ini bener2 bermanfaat buat kita2 nubi di glow engine, pas bgt ni krn hampir tiap mau terbang msti menghadapi kendala settingan, terutama utk glow yg ukrn kecil/25 ke bawah..
NB: Iya nih..brhubung bnyk yg bhs Inggrisnya grothal grathul spt sy(Jw, = kedodoran ) dimohon utk rekan2 yg 'English'nya sdh advance bisa bantu terjemahinnya..

Kayaknya yang dari Satya Wacana kudu nerjemahin nih

Oalah...ngeliat judulnya di "new Post", menarik nih...
Tinggal caplok! Jebule musti di cas, cis, cus dulu....

Lebih enak dalam bhs aslinya biar tidak 'bias' .
Tapi kalau Om joko mau nerjemahin ya ... silakan

[Wind Raider]

Update : terjemahan bebasnya ..
mohon dikoreksi kalau keliru .

[Irwan Bossanova]

untuk suhu wind yg belum saya pahami, kalo kita mau menambah atau mengurangi needle karna terlalu lean ato rich arah putarannya kemana? baik tuk high maunpun low needle. TRus 1 hal lg klo kt pke UBEC 5 volt, tp battry pke 11volt sy lihat UBEC panas, apa itu beresiko BEC terbakar? Mkasih penejlasannya, maklum msih belajar om!

[deninabil]

Mohon ijin ninggalin jejak pak.