Setting up the throttle on the radio and doing the tuning on a new engine have always been a bit of a mystery to me. There seem to be a many subtle adjustments needed between radio and engine to get a really good high end and low engine setting. I basically always end up relying on somebody at the field to do the fine tuning.

So I'm wondering about what "step-by-step" procedures you all might have to do the initial setup and tuning of a newly installed engine? Below is roughtly my "procedure" (but there more guessing the thinking in this).

First, before I take the model to the field, I set up the radio/servo/throttle so that at the top of the throttle trim setting the carb opens full at the full stick position and just a crack open on the idle setting.

Now comes the hard part at the field:

1. Set the needle initially to about three turns open.
2. Set the stick at full throttle.
3. Start the engine.
4. Close down the needle until I get a good high end (with my Saito engine I take that to be in the 9500-10000 range)
5. Move the stick to half throttle.
6. Start adjusting the EPA on the throttle low end so that I get something about right on the idle end of the stick.

At this point I usually have an engine that runs well full open but dies so after I move the stick to idle.

7. Then I start "messing around" with the low throttle setting.
8. Get nowhere.
9. Look around for someone who knows what they are doing!

ALL ADVICE WELCOME!!!

((BTW, this means I did NOT fly the Cub today))

Hi Don,

Here is my way;

* Set the needle at factory settings.
* set throttle stick at high idle position (never at full, thats dangerous in my opinion)
* Switch your glow on
* Start engine
* wait a half to a minute to let the engine come on working temperature
* remove glow switch

Now listening to your engine at the moment you switch off the glow.

Engine dies, you need to adjust the idle needle or the air screw (depends on engine) See manual.
Engine lost some rev's, also need to adjust the idle needle
Engine continues to run without rev's change, idle needle setting is correct

* Then go to full throttle and adjust the high end needle until it is correct.

Happy flying. [8D]

My experience is that when you has setup the needle settings correct (take your time, and be critical to yourself), you almost never have to correct it. The last time I did it in my Waco YMF and Saito 91 is approx. 2 years ago! The only thing I do is start and fly.

Teus

Here is what I like to do.
1) I put the engine on a test stand and use the fuel I intend to fly with.

2) Using 1/3 throttle and electric starter start engine rich.

3) If this is a new engine I will use manufacturers recommendations on break in.

4) After break in gradualy lean neddle valve to produce slightly rich run on high end. Remember fuel/oil mixture is intended to not only to provide combustion but lubrication and to carry away heat generated by the engine.

5) Slowly obtain the slowest idle I can get and still keep the motor running. This step I am using the throttle only, no low end carb adjustments unless the motor will not slow down at all. Most motors today are very close on the low end mixture unless your using a fuel mixture that is a lot different from most sport fuels.

6) A motor that is not broken in will give you fits trying to get it to idle slowly. A dependalbe idle is only possible after the motor is broken in in my opinion.

7) If the motor loads up and dies then adjust the slow end neddle in very small increments of no more than 1/8 turn. If the motor speeds up and dies then richen the low end by 1/8". Repeat step 5.

8) When the motor is installed in the plane I do not use mechanical throttle stop on the carb. I set the idle with the throttle trim on my transmitter. Then I use a throttle cut button or switch on the transmitter to close the carb stopping the motor.

The last few new motors I have purchased required less than a couple of low end adjustments to get a very reliable idle. Once you have completed the above when the motor is installed in your plane it should only require slight (a few clicks) high end needle valve adjustments to produce a good slightly rich high end even through weather changes. Should be no need to play with the low end mixture or at the very most should only need VERY SLIGHT adjustments during initial run.

Also make sure your throttle linkage is not binding or has slop in it. The servo must be able to transmitt mechanicaly the throttle motion from the servo to the throttle arm on the motor without loss of motion! If it does not then you will never achieve precise control.

Hope this helps, it works for me. By the way once I get my motors broken in and mounted in my plane(s) my electric starter becomes a hanger queen. I use a chicken stick and rather enjoy the challenge of getting a motor to start on the first few flips.

Great advice so far! I should have mentioned that this engine is already broken in at I both ran it on a test stand and also had it in another model. So I'm talking about the first time setup in a new model.

First off if you dont have an ear for it, get a tach. Your rpm range is right, but that has to coincide with the right prop. Using the tach start leaning it out until you dont see any gain in rpm and then back down 300-500 rpm. If your engine speed is out of the range you want, then use another prop to get this right. When I move to the low end adjustment and if I have made some pretty big adjustments down there, I will redo the high end as there is a handshake agreement between the high and low and that is how the mid range is set; making sure both are happy together. It might take some back and forth to get right, but when it is, you wont touch anything except in big seasonal changes.

heres mine: plug the lipo into the esc! all done

Yes, but you forgot: charge the lipos, worry about the lipos exploding, selling your car to pay for the lipos...

Seriously, me and electrics are all wrong for each other. I can barely keep my transmitter battery charged and don't know an amp from an ump. There seems to be WAY too many numbers and way too much math involved.

prodigybatteries.com been using them for 4 years very inexpensive. Lipos explode if you short them, use the wrong charger. i keep my lipos in the planes all winter and dont worry. you need to do something drastic to have a problem. Experienced modelers should have no problems.
think of this thar engine is dependent on a tiny coil of nichrome wire that could break at any time. leccy is much more reliable and performance is equivalent

Think about this,I converted a four-stroke backpack blower into an aircraft engine for under $150.Power about equal to a G62.How much would the battery bill be for a small 1/3rd size airplane(not to mention the ESC and motor)?I get a better sound(no WHEEEEEEEEE..),no mess and fuel at the cheap price of @$4 a gallon.Now, before all you electric guys start coming over to my house with torches a'burning,let me say that for anything smaller than a .25 glow motor I do not bother with glow and have been going electric.

Back to the main topic.Lots of good advice here.The one thing I didn't see mentioned is that it possible to have a nice idle and a nice top end but still have it "stumble" or quit altogether when transitioning from idle to top end.When the engine is at idle,pinch the fuel line.If it dies right away,the idle mixture is too lean(usui).If it keeps running and then gains RPM before dying,it is too rich(amai).Words in parentheses are for Don.

Gambatte!

J

It boils down to this: A properly running IC engine is a thing of great beauty. I'll never ever feel that way about an electric motor which will always be about as exciting as my doorbell.

rather not pick my twin up with a garbage bag. SO you are saying my b-25 which is e powered and gives me 15 minute flights is unexciting. functional bomb bay and no holes in the cowl! I run zenoahs in my 1/5 warbirds bit do you know there are motors that will fly that plane. there are excellent sound modules that record the actual engine sound. they sound better than a 2 cycle,
i do fly 4 strokes as i like the way they sound so i do both but for twins e power is the way to go. Its the new revolution in rc. try it dont say its no good

Tim,

My comments are (mostly) tongue-in-cheek. I know you've got some deep experience in both flying and competition as well as with both gas and electric. And I have no doubts that electric is better for certain things. For example, if I ever do a WWI twin (or tri-motor) it'll be be electric. As far as your electric B-25, I'm sure the model is stunning and that flying it is as exciting as it gets. But the electric motor itself? No, I will never have a desire to fondle a brushless motor the way I do a gas engine. I just can't get excited about a coil of wire.

As you know I'm a bit of a purist. Honestly, I love the smoke and the fumes and the smell and the oil and, oh my, that sound! REAL PLANES have real engines. It some convoluted way I actually like knowing that I might find myself in an engine-out situation just like the the pilots back in WWI. Electric might be the inevitable future of RC but it'll be a sad day indeed when gas-powered RC models are a thing of the past something "grampa used to fly."

Sound modules? I'd much rather have an an historically inaccurate REAL sound than a totally scale FAKE sound.

Don

PS. You'll have an extra hard time convincing me today since I got the Cub's engine purring along and ticking over like a clock at 2800. When engines are working they are pure joy!

Next time I have an extra $500-600 or so to invest in a 50-class electric motor, suitable ESC, LIPO batteries, suitable charger, and assorted "electric accessories," I'll give it a try.

But out of curiousity, let's take for example, my next major project, a 1/6 scale Albatros CI with a 85" (top) wingspan. What would be the list of electric components and prices I would need for something like this. At this moment we're planning to use an RCV 91CD. Since the CI has a pointy nose the only way to deal with this is to mount the engine sideways so that we have at least one clean side view (the left side) and can use a full dummy of the Mercedes engine. But I suppose electric (probably with a shaft extension) is worth considering.

But really what would it take and what would it cost. First or all what would be the equivalent in terms of Engine size?

Electric gets real expensive real fast at larger sizes, and if you like to fly, you need multiple batteries, or you're spending all of your time waiting for batteries to charge.
Back to your engine. If it's a Saito you're talking about, you MUST adjust the low speed needle. On my 1.80 it took about 3+ turns in to get it leaned from the break in setting. I always get my needles set on a test stand first. On my saito's I peak the HS needle WITH A TACH! then leave it at peak, for now. Lower the throttle setting to the lowest idle possible, then start leaning the LS needle. let it run for a few seconds after changing the needle. Check transition after you lean it each time. Keep leaning until it stumbles on transition, then richen about 1/8th turn. Re-peak the HS, then richen 300-400 rpm for flying. If you don't lean the LS on a Saito, it will idle poorly, run rough, and use a lot of fuel. My 180 will idle as low as 1350 rpm and all day at 1800rpm, and my .40a will idle as low as 1600 rpm an all day at 2000.

That's pretty close to what I ended up doing (with some help at the field). I'm impressed by the low idle rpm's! I have my 56 idling at around 2800 (which is slow enough that the model doesn't want to move on the ground). How slow is slow enough?

Don,

Just as an aside, attach a stick or similar to your electric starter, and tach' it. Let's say it spins at 2500rpm. Now get your engine running at the same rpm, say 2500, and look where the throttle stick is. THAT is a good place to set the throttle on start-up, as it will be the speed the tacho spins (roughly - load slows it a bit). For my .50 - .90 4-strokes, it's usually a bit above idle.

Once you've set your full-throttle mixture (via main needle) with the stick firewalled, pull it RIGHT back with the trim up, and use EPA to get a reliable slow idle. Then bang it open - cut is lean idle, splutter is rich idle - tweak idle screw until get a smooth transition from idle. Once done, pulling the trim back (when at idle) should cut it.

I generally set my idle a bit on the high side for safety, then go back to mid-trim when preparing to land. So full up trim is fast idle, centred is slow idle, full down trim cuts the motor.

Just be slow and methodical and you'll be fine - I'll often spend a session at the field with a new plane just twiddling the engine and not even fly, which takes the pressure off. Go home, tighten all the loose screws then fly it next time out.

Cheers,

Cam

Nice tip, that! I noticed at the field today that the electric starter seemed to be outspinning the engine at the "couple clicks above idle" position and it didn't feel good.

Actually this is exactly what I ended up doing yesterday.

It has a good clean ideal but I did notice today that the mi-range is a bit sloppy (unresponsive). So there's more tweaking to do. Still today it was idling steadily at 2500 with the trim a couple clicks down from the top.

Me too. But this always seemed like just a "bad habit" because I didn't have my idle set properly.

[/quote]
Just be slow and methodical and you'll be fine - I'll often spend a session at the field with a new plane just twiddling the engine and not even fly, which takes the pressure off. Go home, tighten all the loose screws then fly it next time out.
[/quote]

Absolutely! I figure a new model also gets the jitters and needs a couple of trips to the field before it flies just to get used to the place!

there are new sound modules that actually record the read sound of the engine in your plane . 3 4 inch speakers are used. You make a sound box and wow. ram sound stuff is not very good , this system is made in brazil i believe. ill do a google and find the url


Benedini sound systems featured here on rcu google that name and you wont believe it. Dont get me wrong I have a stearman, tiger moth 1/5 p-47 and a 1/7 p-47 all saito and zenoah and they run great. However for twins i go for electric. I am finding that with that sound systen i may go all e power. Money is no object planes come first

I'm not sure I could get my wife on board with that.

aerosoundrc.com you cant tell me thats not cool. mine lets me build in the living room she says as long as the bills are paid its better that the bar. You need to know my wife is disabled and doesnt go anywhere, I would trade all the rc planes i have for her to be the way she was before she broke her back. She has a permanent morphine pump
That said think of complete scale outlines no holes on the cowl look at the p-47 vid on that web site the p-51 owner drilled holes in his cowl (yuk) its just nice not to deal with starting issues. prodigtbatteries.com is where i get my batts they are cheap but very good i use these exclusivly. hacker geared motors can go for 600 a motor! thats what is in that p-47 theay are geared and narrow and allow you to fit a scale en gine up front. My twins use axi outrunners 120 per moter each esc 180 so its not cheap but convinient.
Im building a 1/9th wingspan b-17 that wil be a leccy!

http://aerosoundrc.com/demos.htm

Yes, that's cool. And it IS proportional to the throttle position! But I would imagine building in a speaker system has it's own problems.

Also you could have a Cub sounding like a P-51.

hey are you in the service and thats why you live in japan.. See i told you guys! cool eh, think of a total scale engine like in the p-47 on the site

Might be cool just for gun sound, TAT,TAT,TAT....TAT,TAT,TAT...... and I worry about finding money for my next aluminum pot, erh, cowl! [sm=wink_smile.gif] Just curious but how much would all the sound stuff weigh?

its all on the web site maybe 14-18oz
not that much in a 1/5 scale fighter

remeber this web site is not ram they are not very good. IDK if these guys do gun sounds