HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 19, 2009, 04:50 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
Discussion
cox engine problems

hi my cox .049 will start and run for about 1 to 4 seconds and then it just winds down and dies. The needle valve dont seem to affect the problem much.Could this be from a dirty engine.A guy gave it to me and i dont know what he did with it .Even when i make it really rich or really lean nothing happens.Ill prime it and it will start fine but then just dies.Any advice.I am running 15 % caus thats all my hobby shop has .
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Sign up now
to remove ads between posts
Old May 19, 2009, 06:48 PM
Registered User
digdugb17's Avatar
Fortson, Georgia
Joined Sep 2004
126 Posts
Try opening the needle to 4 1/2 turn, normal is 3 1/2 turns, try to start it a few times, if that does not work close 1/8th turn, try a few times, then repeat the 1/8th close a few times
digdugb17 is offline Find More Posts by digdugb17
Reply With Quote
Old May 19, 2009, 06:58 PM
Registered User
Joined Oct 2008
816 Posts
Can't say where to start first.

Quote: "A guy gave it to me and i dont know what he did with it ."

I guess we need to start with the guy that gave it to you. Ask him what he did with it. I cannot imagine someone nice enough to give you an engine would not try to be helpful otherwise. Could you ask him to help you run it? You know, still you get the hang of it?

Quote: "caus thats all my hobby shop has ."
Any hobby shop has the ability to order what you need. What you need is Sig Champion all castor fuel:
http://www.sigmfg.com/IndexText/SIGCF100.html
Cox engines love all castor fuel and more nitro if you can.

Can you post a picture of the engine? Cox made a lot of engines and it can make a difference which one you have to try to help you.

Quote: "will start and run for about 1 to 4 seconds and then it just winds down and dies. The needle valve dont seem to affect the problem much."

It sounds like you are on the right track regarding the fuel starvation. Need to find out if you have a reed valve engine or rotary valve engine.

Could very well be a dirty engine but depending what type Cox engine you have can help point the way to getting you up and running!
LT
lightthings is offline Find More Posts by lightthings
Reply With Quote
Old May 19, 2009, 10:12 PM
Registered User
Joined Apr 2007
70 Posts
Sounds like your not getting fuel. I'd bet that the reed does not have enough play in it. The reed is held in place by a gusset or a spring. It needs to be able to move, should have some play in it.
Adduckted is offline Find More Posts by Adduckted
Reply With Quote
Old May 20, 2009, 12:51 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
I think i have found out what the problem is.The the crankcase is losing compression.The gasket that should have been thier is not any more.I have tried runnig with a richer setting and no progress.Is there any way to fix the the leak.It starts really easy but you can see bubbles coming out the joint.Would i be able to make a gasket out of hi temp silacone.The engine is the cox rr1.The red has plenty of play.Thanks for the advise.O and were would i be able to buy a ne engine if i cant get this one to work.I have cheked the cox sight and i cant find any.I have heard you can buy them cheep.
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Old May 20, 2009, 01:31 PM
Registered User
Concord,NC
Joined Sep 2003
182 Posts
Can't be a RR1 as they are not reed valve engines. You can make a gasket out of an old playing card.

Tim
Tim Wiltse is offline Find More Posts by Tim Wiltse
Reply With Quote
Old May 20, 2009, 06:45 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
I know its a rr1 i looked it up.Im not sure what kind of valve it has.So the playing card would work?Ill have to try that.Where is the best place to by .049 moters?Thanks
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Old May 20, 2009, 08:08 PM
Registered User
Concord,NC
Joined Sep 2003
182 Posts
raptor,

The Cox RR1 is a drum rotor engine so of course it has no reed. On top of needing a crankcase to tank gasket I would dare to say the engine needs a good cleaning. Take the tank/backplate off the engine and remove the needle valve stem from the backplate. Get a flashlight or other light source and shine it through the venturi/intake hole of the backplate. While looking down the hole you took the needle valve stem out of you should see a very small opening at the bottom of the hole. If not it's gummed up from old left over fuel. You can take a couple of cups of water and a couple of drops of liquid dishwater machine soap NOT normal dish soap. Heat it to a very low boil with the backplate in it for a few minutes and it should clean it out. Replace the intake fuel line while you are at it. Also there is a small black o-ring type gasket the goes on the end of the venturi tube and seals against the backplate. You will have to make it out of small fuel tubing. It's easy to make just slice a small piece off the fuel tubing. Might take a couple of tries but you can do it. Easy putting the engine back together as the drum rotor needs to key into the pin on the crankpin.

Do you have a Series 1 or 2 RR1? Is the crankcase gold or plain aluminum? What kind of shape is the blue anodizing on the tank? Keep in mind a real Cox RR1 is worth around $100 for a pretty ratty used one to $500 NIB!!!

Tim
Tim Wiltse is offline Find More Posts by Tim Wiltse
Last edited by Tim Wiltse; May 20, 2009 at 09:41 PM.
Reply With Quote
Old May 20, 2009, 10:32 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
The crank case is gold.I have cleaned fairly well.The blue anodizing is in fairly good condition. There are some small worn off places.But it still is pretty good.Is the gold crankcase sieries 1 or 2 ?Is the venturi hole the hole that comes out the back or where the needle valve screws in?I have not used these small engines for very long.Wow i didnt know they were worth that much.Thanks. Raptor
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Old May 20, 2009, 10:40 PM
Registered User
Concord,NC
Joined Sep 2003
182 Posts
Raptor,

The gold crankcase is the Series 2 RR1's. The venturi hole would be the hole that come out the back. But the light in the venturi hole and look down the needle valve hole to see if it's blocked. There is a very small hole at the very bottom of the needle valve hole.

Tim
Tim Wiltse is offline Find More Posts by Tim Wiltse
Reply With Quote
Old May 21, 2009, 09:27 AM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
Ok got it.Ill check it out .If this engine was working correctly how much power would it have compared to other .049s?
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Old May 21, 2009, 06:28 PM
Registered User
Concord,NC
Joined Sep 2003
182 Posts
Raptor,

That is open for debate. I have had several RR1's go through my hands. Both those that I have owned and those that I have restored for customer on mine. I have only ran two myself. They were great little engines. Power was on par with a good Black Widow. To each their own of course but if you are looking to fly I and not become an engine collector then sell the RR1 and buy something newer. You have many sources for engines. Cox reed valve .049's for a few places. I myself sell modified Cox reed valve engines. I also build and sell a modern version of the RR1 called the Mangusta DR .049. There is AP Wasp .061's from Hobby People. These come with a throttle. Brodak sells 2 versions on their .049/.061 sport engines. Then of course you have the big players in 1/2a Fora and Profi make racing engines that turn in the area of 30,000rpm for around $150.00 and the Mac Daddy the Cyclon 1/2a's are high 30,000rpm monsters and run around $200 I think these days.

Take care,
Tim
Tim Wiltse is offline Find More Posts by Tim Wiltse
Reply With Quote
Old May 21, 2009, 06:55 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
How much do you sell your engines for?Is the cox .049 sure start a good engine?Or at least good enough to use.In yhat picture does that use a external fuel tank?I have heard you can buy the sure starts pretty cheap.Is that picture one you made?

Thanks for the info
Raptor
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Old May 21, 2009, 07:15 PM
Registered User
Concord,NC
Joined Sep 2003
182 Posts
Raptor,

Yes the engine in the picture is one of my Mangusta DR .049's. It is a rear drum rotor engine like your RR1. The Sure Start is a good little engine. New straight out of the package they need alittle work before you run them i.e .connecting rod reset, crankcase cleaned out etc. The great thing about the Cox Sure Start is you can do so much with them. Slow and easy flying on the stock engine or fast and on the edge with one of my tweaked Skyline F/X .049's. I'll PM you about them as I don't want to clog the forum up with business.

Take care,
Tim
Tim Wiltse is offline Find More Posts by Tim Wiltse
Reply With Quote
Old May 22, 2009, 01:19 PM
pro heli crasher
Trout Creek MT
Joined Oct 2008
50 Posts
Thanks
raptor fan is offline Find More Posts by raptor fan
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Cox engine users? PROACE Fuel Plane Talk 44 May 23, 2009 08:02 AM
Discussion Cox engine problems Bevan Jones 1/2A Planes 16 Dec 06, 2007 09:52 PM
Zagi 400X - Engine Problems sbuechler66 Foamies (Kits) 7 Sep 10, 2001 06:43 PM