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May 15, 2006, 05:28 AM
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What is Lean and Rich?

I'm a beginner and I've heard people talking about running the engine on lean or running it rich, what does that mean? and how do we do that and what are the advantages and disadvantages in comparison.
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May 15, 2006, 07:07 AM
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Welcome to the forum. This has been posted in the electric beginner training area (hopefully someone can move it to the glow beginner area), but lucky for you some of us read both areas

Glow engines (and diesels and petrol engines) run on a mixture of fuel and air. There's a theoretical and practical ratio of air to fuel that will give you the most efficient running -- it's about 14:1 for a petrol engine, don't know what it is for glow, but the actual number doesn't matter anyway.

If you go too rich (too much fuel compared with the amount of air) the engine will not rev quite so fast at full throttle and, in extreme, may actually stop running because it doesn't have enough air. But a little bit rich is normally good because it means there's more oil (in the fuel) going through the engine which will ensure that it gets well lubricated and keeps cooler.

If you go too lean (too little fuel compared with the amount of air) the engine will also not rev quite so fast a full throttle and, in the extreme, will stop running because it doesn't have enough fuel. Lean is not good because it means there's no oil left over (it's all burned) to lubricate the engine, so it will overheat and seize up.

When you go vertical the engine often tends to lean out a bit due to having to suck the fuel up from the tank, which is then below it, rather than having it flow in. To avoid that you always start with the engine a little bit rich.

You get the right richness, once you've got the engine running, by adjusting the main needle until you hear the revs reach a maximum (which indicates exactly the right mixture), and then opening the needle about 1/8 of a turn. You check it by opening the throttle to full or near-full, then holding the plane in a vertical position and listening to see if the revs drop at all. If they do drop it's probably because it has leaned-out a bit when you lifted it up, so you put the model down, throttle back to idle, and open the needle a bit more and try again. You may need someone to help with this
May 15, 2006, 12:31 PM
Foam flies better
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It reffers to the amount of fuel entering a glow or gas engine. Post it in the gas begginer forum, thats where the gassies hang out.
May 15, 2006, 01:00 PM
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thanks abenn for a descriptive answer, i really appreciate that. Thanks Fly or die too, I'll post it there too to see what others have to say. Thanks again.
May 15, 2006, 01:10 PM
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Fly Electric and do not worry about it.

Ex Glow Flyer.

May 16, 2006, 04:34 PM
Given up counting
alexeames's Avatar
What's lean and rich?

Cameron Diaz
Kate Moss

Where are you Usta, thought you'd get there first with that one?

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