longdan

Is it possible to take a carb body from a cox Medallion, cut off the venturi, tap it out and screw in a venturi/NV assembly from a TD?

Jim Thomerson

Don't know, but the thread is 1/4 x 32 same as glowplug.

ffkiwi

Yes-but why bother? TD's fitted with Medallion carb bodies run just as well as they do on the original set up. The key to the TD'd performance is (i) the crankshaft, (ii) the cylinder porting and (iii) the head-the carburetion comes a very poor 4th.

In fact on reflection, I would not recommend cutting down the Medallion unit at all-I suspect the neck portion would be barely adequate in diameter to take a 1/4-32 thread. TDs are fairly chunky in that area and were still prone to splitting. There was a variant 051 TD housing done with a thick plastic web behind the venturi spigot-I have an 051 engine so fitted-but they are not common.

'ffkiwi'

Silvaire

My Feedback: (50)

The TD 051 housing that you refer to was specific to the TD 05 RC. The "thick plastic web behind the venturi" fit into a notch in the base of the muffler assembly to position and prevent the muffler from rotating on the cylinder.

(The "thick plastic web" then became the weakest part of the venturi, as it easily broke when the muffler contacted the ground in even a rather minor crash.)

Arlen

longdan

Because I have a medallion carb body, but no NV or spray bar for it, otherwise I would just use it as is.

ffkiwi

The TD 051 housing that you refer to was specific to the TD 05 RC. The "thick plastic web behind the venturi" fit into a notch in the base of the muffler assembly to position and prevent the muffler from rotating on the cylinder.

(The "thick plastic web" then became the weakest part of the venturi, as it easily broke when the muffler contacted the ground in even a rather minor crash.)

Arlen


That's interesting-I've learnt something today. My 051 (and it is an 051) came from ebay several years ago, and is the standard FF/UC version-so it would appear someone retrofitted the 05 R/C assembly to this particular motor. I'm not complaining as in this form it is stronger than the standard unit.

'ffkiwi'

SGC

longdan, Have you any Cox product 049's ? the spraybars came in different dia's you may find 1 that will fit the medallion . The original medalion spraybar is held in with a circlip and uses the same needle as the early metal backed Babe Bee.
Stewart

BMatthews

I know that the early product engine spraybars fit the Medallion body. A buddy did one that way.

ffkiwi

[quote]ORIGINAL: ffkiwi


In fact on reflection, I would not recommend cutting down the Medallion unit at all-I suspect the neck portion would be barely adequate in diameter to take a 1/4-32 thread. TDs are fairly chunky in that area and were still prone to splitting. There was a variant 051 TD housing done with a thick plastic web behind the venturi spigot-I have an 051 engine so fitted-but they are not common.

....having checked a Medallion 049 housing at 0.3" OD in the neck region, by the time you tap it 1/4-32, you will have a wall thickness of only 0.025" the wall thickness on a TD housing is almost double that at 0.046". Whilst it may be physically possible I stand by my earlier comment in the quote above-the wall thickness and consequent strength would be inadequate. if you're unable to find a Cox Medallion 049 spraybar assembly (the 049 and 09 Medallions used the same assembly) you could try using something like a DC, AM or OS Pet NVA. It won't look pretty-but it will work. You may have to use packing washers on one side or the other on the spraybar to adjust the location of the jet hole to a central position.

Failing that Texas Timers does a nice aftermarket fine thread needle valve assembly that will fit a Medallion 049. There are details of fitting one to a Medallion on his website.

'ffkiwi'