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Surestart with carburator mod bench test Babe_b10
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Surestart with carburator mod bench test

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Surestart with carburator mod bench test Empty Surestart with carburator mod bench test

Post  Gordinir8 on Wed Aug 12, 2020 12:26 pm

So here is a video of my sure start bench test with carburetor on, manage to adjust revs from 13500 to 11500, don't know if it can be better but this is it. Next test will be with a throttle sleeve when i get one.
Thomas
https://www.youtube.com/watch?v=UVqKXkW-7bg
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Post  MauricioB on Wed Aug 12, 2020 1:25 pm

Welcome to the forum !.
You should have a wider rev range with the air valve. Between 7000 and 15000 rpm approx, depending on the fuel and the propeller you use.
Check the carburetion from the needle and repeat the operation.
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Post  Gordinir8 on Wed Aug 12, 2020 1:47 pm

Hi, what do you mean to check carb from the needle? You mean I should also adjust needle when at "idle"?
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Post  MauricioB on Wed Aug 12, 2020 1:59 pm

Raise the fuel tank as I show in the capture of your video.
Close the entire needle and open it about 3 1/2 turns.
Start the engine.
Keep the air valve fully open.
Once running, close the needle until reaching the maximum rpm.
Open the discharge needle just a few clicks.
Begin to close the air valve.
We see what happens.
Surestart with carburator mod bench test Tanque10
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Post  Gordinir8 on Thu Aug 13, 2020 3:35 pm

Test again today as you said, raised the tank, run at about 3 turns open, lean it for max rpm and open up again the needle just a few clicks. When i closed the air valve and got about 2000rpm lower and then dies. I am running a 12% nitro fuel if that matters. (there is no difference from fully open to 3/4 closed of the airvalve). Also when you referring to ''discharge needle'' you mean the needle right? There is only one needle in my setup.

Thomas
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Post  robot797 on Thu Aug 13, 2020 3:38 pm

I like your starter
were did you get it
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Post  Gordinir8 on Thu Aug 13, 2020 3:47 pm

Its a nice compact little starter that i design it my self and then 3d printed it. I have plans of selling (just the case) without the 540 motor, battery etc to anyone interested but i have to check the final cost as well as shipping charges before i set the final price. So stay tuned for this one.

Thomas
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Post  robot797 on Thu Aug 13, 2020 3:48 pm

you you make it a complete usable kit
I am interested
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Post  Gordinir8 on Thu Aug 13, 2020 3:58 pm

Thank you, i will let everyone know when ready, but not sure for a full kit yet.
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Post  Surfer_kris on Thu Aug 13, 2020 4:05 pm

These are not RC-carbs but merely a a cold start choke, so they will reduce rpm mainly by making the engine run richer (plus restricting the air flow), there are lots of threads on this earlier on this forum.

What prop size are you using?
It seems like the prop load is too large, this makes the top rpm low and the needle setting has to be rich already at the top rpm. So then with the choke applied it easily/quickly goes too rich and dies.

With a smaller prop load you will be able to lean out the engine further and get a higher top rpm. The engine will then likely tolerate more of the choke, thus producing a lower lowest rpm, before it is choked too much and stops.

More nitro in the fuel also tends to provide a broader needle setting and thus a higher tolerance to the choke, so that might be worth testing too.
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Post  Gordinir8 on Thu Aug 13, 2020 4:45 pm

Prop is 6x3 but I can test a 5x4 that I have or a 3 blade 5x3 I might test it tomorrow again with the smaller prop. Is there any standard size for this engines?
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Post  MauricioB on Thu Aug 13, 2020 4:47 pm

Ok, buddy, if you've made those corrections, your glow plug may "go off" when you start to close the air valve.
I have noticed that some glow plugs are hotter than others, although they are all sold equally.
Maybe your glow plug is "cold" or that it is with some wear and does not maintain the necessary incandescence to maintain the explosion.
You can do two things and try:
1) Change your glow plug for another and do the test.
2) Add a fuel with 20% nitro.
If that doesn't help, then there is another problem that I can't detect.
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Post  MauricioB on Thu Aug 13, 2020 10:05 pm

Here I make a very short video, since my neighbors sleep sleep !! ... Shh Shh .... Very Happy
Cox .049
Regulator - air valve
Propeller 6x4
RPM: 8000/15000
Nitro: 20%
Glow Plug: (not original) (Merlin type)

Remember: that it IS NOT A CARBURETOR, the air valve is not instantaneous, it has a slowdown when accelerating and decelerating the engine.
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Post  Gordinir8 on Fri Aug 14, 2020 4:59 am

Fuel might be the answer although I want to try one of this heads, what type of plug it is, I might convert one of my heads. Nice run by the way. I have run my neighbors nuts the last couple of days I guess 😂
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Post  MauricioB on Fri Aug 14, 2020 8:14 am

Do not modify your glow plug, try another one if you have one and go for nitro at 20%.
In any case, you can see to get this type of glow plug that this engine has and that I leave a link for you to guide.
http://www.exmodelengines.com/product.php?productid=17871&cat=279&page=1
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