Some cox questions
02-29-2004, 03:32 AM
#1
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Some cox questions
Hi everybody. i have a couple of questions again 
.
i got a brandnew black widow. it came with a black plastic backplate. but either the seller tricked me and changed the backplate on it or one of the screws had been forced a little bit. there are marks around srew hole. and that particular screw goes in more than the others. it leaks alittle bit. so i decided to switch it with my golden bees metal backplate. from outside it looks it fit perfectly. but i havent get a chance to run it yet. Is there any disadvantage by doing this. the only difference i can see between these two backplates is that the hole where engine takes air in is slightly smaller inside on the metal one.
if i get a muffler for a .049 how much difference will be there(sound and power)
And i also got a medallion .09 off ebay. its brand new. and i need some suggestions about what plane to get for it. i like piper cubs. i have one and i wouldnt mind having another. Is there any piper j3 kit out there for my medallion .09? or any easy(and slow) flying cub like plane.
And finally i want to have a throttle sleeve for this medallion. do they throttle well?? any body has any extra sleeves??
thanks for any input
EC
.i got a brandnew black widow. it came with a black plastic backplate. but either the seller tricked me and changed the backplate on it or one of the screws had been forced a little bit. there are marks around srew hole. and that particular screw goes in more than the others. it leaks alittle bit. so i decided to switch it with my golden bees metal backplate. from outside it looks it fit perfectly. but i havent get a chance to run it yet. Is there any disadvantage by doing this. the only difference i can see between these two backplates is that the hole where engine takes air in is slightly smaller inside on the metal one.
if i get a muffler for a .049 how much difference will be there(sound and power)
And i also got a medallion .09 off ebay. its brand new. and i need some suggestions about what plane to get for it. i like piper cubs. i have one and i wouldnt mind having another. Is there any piper j3 kit out there for my medallion .09? or any easy(and slow) flying cub like plane.
And finally i want to have a throttle sleeve for this medallion. do they throttle well?? any body has any extra sleeves??
thanks for any input
EC
02-29-2004, 01:46 PM
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RE: Some cox questions
Hello,
The Metal backplate will probally give a bit less power. You can check the plastic one , hold it up to a good light source & push with a small screwdriver on the "trouble spot" inspecting for hidden minor cracks in the screw hole. I have used silicone rubber in these on the outside of the engine before to halt minor leaks, just start the screw& before it seats, cover it by pushing in the goo before you tighten the screw, then let it set. Only on the outside, I have tried this.
A muffler will rob LOTS of power ,more so if the engine cylinder has sub induction , up to 30% possable loss from it. If you use the metal backplate, I would suggest letting it scream!
I have had problems with throttle sleeves on medallions, you have to find the ones that fit proper. I have one for a .049 that will not turn on the Medallion, it is too tall. It could be cut down, but I did not wish to do the mod. I think the newer ones have a muffler built in, that could be what to look for.
Not sure about the Cub, they are great flyers though!
Best,
Remby
The Metal backplate will probally give a bit less power. You can check the plastic one , hold it up to a good light source & push with a small screwdriver on the "trouble spot" inspecting for hidden minor cracks in the screw hole. I have used silicone rubber in these on the outside of the engine before to halt minor leaks, just start the screw& before it seats, cover it by pushing in the goo before you tighten the screw, then let it set. Only on the outside, I have tried this.
A muffler will rob LOTS of power ,more so if the engine cylinder has sub induction , up to 30% possable loss from it. If you use the metal backplate, I would suggest letting it scream!
I have had problems with throttle sleeves on medallions, you have to find the ones that fit proper. I have one for a .049 that will not turn on the Medallion, it is too tall. It could be cut down, but I did not wish to do the mod. I think the newer ones have a muffler built in, that could be what to look for.
Not sure about the Cub, they are great flyers though!
Best,
Remby
02-29-2004, 02:56 PM
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RE: Some cox questions
Hello encan,
My take on the backplate thing, is the cox company was sold and they got cheep. They went to a plastic backplate to save money and they do come on the newer Black Widows.
The plastic ones are good I guess, but for my money I would rather have the older style Black Widow with the metal plate.
As for the hole being bigger.
They have taken to enlarging the hole to get more power from the engine. I would run it with the stock metal back plate with the smaller hole and see if it works out, if not start enlarging.
I have not done this myself, so ask the folks here and someone will have the answers to the question of what is the maximum size you should ever go.
A muffler, like Remby said, is a power sucker. It is necessary if you have really strict noise control where you fly. Most of us are lucky enough to fly where you don't need them. Don't use it if you don't have to.
I have noticed that the throttle sleeves do come on the medallions, but in general they are not too effective. If you have an original one you might have moderate success, but trying to match one to yours is tough. The tolerances have to be very tight to make the thing work.
I have a few sleeves and they are all just a little different.
I have used .09s to haul up powered gliders and some larger (large for 1/2 A) planes. They have a lot of power and run very well. I would build a plane for that engine, it is is a piper cub use one that would take a .10 - .15 and strap the .09 to it.
Good luck,
MR Flyer57
My take on the backplate thing, is the cox company was sold and they got cheep. They went to a plastic backplate to save money and they do come on the newer Black Widows.
The plastic ones are good I guess, but for my money I would rather have the older style Black Widow with the metal plate.
As for the hole being bigger.
They have taken to enlarging the hole to get more power from the engine. I would run it with the stock metal back plate with the smaller hole and see if it works out, if not start enlarging.
I have not done this myself, so ask the folks here and someone will have the answers to the question of what is the maximum size you should ever go.
A muffler, like Remby said, is a power sucker. It is necessary if you have really strict noise control where you fly. Most of us are lucky enough to fly where you don't need them. Don't use it if you don't have to.
I have noticed that the throttle sleeves do come on the medallions, but in general they are not too effective. If you have an original one you might have moderate success, but trying to match one to yours is tough. The tolerances have to be very tight to make the thing work.
I have a few sleeves and they are all just a little different.
I have used .09s to haul up powered gliders and some larger (large for 1/2 A) planes. They have a lot of power and run very well. I would build a plane for that engine, it is is a piper cub use one that would take a .10 - .15 and strap the .09 to it.
Good luck,
MR Flyer57
02-29-2004, 03:45 PM
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RE: Some cox questions
Encan,
Go ahead and use the Golden Bee's metal backplate. Don't worry that it's hole may be smaller than the hole in the tank tube. Just make sure that backplates hole is NOT bigger than the tank hole or you will have fuel draw problems. The metal backplate is stronger anyways.
The Cox mufflers do almost nothing for noise, they just rob power!
Later,
Tim
Go ahead and use the Golden Bee's metal backplate. Don't worry that it's hole may be smaller than the hole in the tank tube. Just make sure that backplates hole is NOT bigger than the tank hole or you will have fuel draw problems. The metal backplate is stronger anyways.
The Cox mufflers do almost nothing for noise, they just rob power!
Later,
Tim
03-01-2004, 12:26 PM
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RE: Some cox questions
Unfortunately, there are "new" and "old" plastic backplates. For once, the new ones are better!
When they designed the plastic backplate, they left the bottoms of the screw wells with sharp corners. With vibration or even over-torquing of the screws, the bottom would split.
I had them change to a small radius in the bottom corner, and that was the end of the problem.
Also unfortunately, you can only find out if yours has the correction by removing one of the screws and examining the bottom of the screw well with a powerful magnifier.
But such is life...
When they designed the plastic backplate, they left the bottoms of the screw wells with sharp corners. With vibration or even over-torquing of the screws, the bottom would split.
I had them change to a small radius in the bottom corner, and that was the end of the problem.
Also unfortunately, you can only find out if yours has the correction by removing one of the screws and examining the bottom of the screw well with a powerful magnifier.
But such is life...
