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Old Mar 21, 2008, 01:18 AM
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Question

Cox Sure Start .049


First of all, this engine runs well. The only problem I have is how to set up the fuel system. There is no muffler pressure so I assume its gravity fed , however, I have never done that and am not sure how one would go about it. Any help would be appreciated.

Eric
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Old Mar 21, 2008, 05:15 PM
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it's a reedie! don't worry about it, just mount your tank about level with the engine and hook it up!

Regards,

Nick.
Old Mar 21, 2008, 06:01 PM
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Eric, up until the 70s very few model engines had mufflers and ran no preesure at all. If you do a bit of reading you will see how the flow of air into the engine's crankcase creates a partial vacum that pulls the fuel in. In the mean time just run the Cox and enjoy!
Old Mar 22, 2008, 02:14 AM
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Cool! Thanks guys it runs very well. I like it!

I rigged up the tank so that fuel flows in... works well... its just that initially there is like an air bubble between the fuel flow and engine, but once thats gone it runs great! Getting rid of the air bubble is the only thing I am not sure of. It works to pull the line off the engine and reconnect it but fuel is wasted on the ground. Can I just turn the propeller backwards a couple times to clear the air pocket?

Eric
Old Mar 22, 2008, 02:22 PM
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cover the intake with your finger and suck the air bubble in. it'll be fine. what are you gonna put it on? i wanna put one of mine(black widow) on a 30 inch boomer. hehehe...

Regards,

Nick.
Old Mar 22, 2008, 02:51 PM
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I'm putting it in THIS!

http://www.guillow.com/kitimages/700/prod_det_801.jpg
Last edited by EricClark; Mar 22, 2008 at 02:57 PM.
Old Mar 22, 2008, 05:14 PM
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28 inches is really small for an .049... be ready for one hell of a ride. also, you should reinforce the hell out of it. guillows balsa is really flimsy and soft, an .049 would rip it to shreds without re-enforcement.

Regards,

Nick
Old Mar 22, 2008, 08:19 PM
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Hmm. Ok, well I don't really know the power of glow engines in comparison to a model so I'll take your work for it. Its just that on the box it say .049 to .15 U-Control or .049 FF. So I thought I was safe using the smallest size. Ah well, we shall see.

Eric
Old Mar 22, 2008, 09:22 PM
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You will be fine with a sure start in there. Those sure starts are not the power meisters that the TD's were. A 28 inch wingspan biplane has a lot more drag than even a 36 inch monoplane like the corsair or the Hellcat and I did many successful conversions with them.
I do agree with the "beef it up" notion. I would certainly plank the entire fuselage and a good part of both wings with 1/32 balsa.
Good luck.
JEFF
Old Mar 22, 2008, 10:55 PM
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Thanks to all of you who responded. Here's a pic of my .049 with the modded head for a glow plug. I like it.

Eric
Old Mar 22, 2008, 11:21 PM
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Getting the fuel to the engine is pretty easy. When you fill the tank for the last second or two close the overflow. That will force fuel through the fuel line and give a small prime to the motor. You do not want to over prime it but thats unlikely if you do not seal off the overflow on the tank for more than a few seconds.
Bob
Old Mar 22, 2008, 11:48 PM
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Thanks Bob!
Old Mar 23, 2008, 12:06 AM
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cool! where'd you get the plug head? and does it hurt performance at all?

Regards,

Nick.

P.S.: you better put that mounting screw back in!
Old Mar 23, 2008, 12:28 AM
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Cox engines were known for their fuel draw; seems to me that Peter Chinn measured fuel draw on a TD049 at 43"!
Old Mar 23, 2008, 01:41 AM
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Nick,

I don't know about the performance cause I just got it today.

I got it here.

Eric


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