Mating a Cox Tee Dee .09 to an Enya .09-III carburetor

Parts to order to do this modification:
Cox .09 Tee Dee Carburetor Body (Aluminum) from either Ex Model Engines or Cox International.
Enya .09-III carburetor – part number 09330

The photos below are of the Enya .09-IV Quicky carburetor






Unfortunately, the Enya .09-III carburetor is undersized to try to tap the threads on it to thread into the Tee Dee carburetor body (aluminum). The o.d. of the carburetor measures about 7.0mm and the threaded hole on the carburetor body measures 7.08mm
So, the carb slips in nicely into the carb. body.




What has to be done then is to modify the carb. body to make the Enya carb. Fit to the Cox engine.
First thing is to remove the radius off the carb. body where it transitions from the crankcase to the carb.
This also will be our area for the screws that are on the Enya carb to secure the carb onto the carb. Body.
At the top, where the carb slips in, is our flat (straight area) use that area to have as your depth to mill away the aluminum to make the mounting area for our screws.





I using a 3/8” end mill and clamping the carb. body in my mill’s vice, clamping on the front and back of the carb. body and lining up the carb face on the body at 90 degrees to the mill’s table.
Next was to rotate my mill’s vice so that the carb section was in the same axis as my mill when I cranked the handle for milling (less than 45 degrees – 30 some degrees))
I carefully milled in the center of the venturi section where the carb will go to a depth of 6mm from the face. (to clear screw head size).



This was done on one side then the other as well.

Next was to drill the clearance holes for the Enya carb. mounting screws.
With my vice still set at the correct angle, I figured out the center of the hole using a lettered drill bit (“K”) in the carb. body hole, touching it with my center bit and ½ that to get my center.
Then I measured on the Enya carb the hole depth of the screws. From there I was able to get the depth to where I needed to droll the holes.



I center drilled the one side. Then changed to a clearance drill needed for the screws and drilled the hole all the way through to the other side.

Took out the carb. body out of my mill’s vice and installed the Enya carb to the Cox carb. body.

So far so good!

Last thing I had to do was to shorten the stem on the Enya carb that went into the Cox carb. body.
It was sticking down too low to where it would not let the carb. body be assembled onto the Cox engine.
I test fitted it a few times to make sure there was no rubbing or binding from the carb when assembled.



That done, I used a little Permatex gasket sealant on the Cox carb. body at the usual locations and assembled the engine and let it sit over night to cure.

Last to do was to assemble the Enya .09-III carb onto the Cox .09 engine.
About 2 weeks later I had the chance to run the engine and it did just about as well (maybe better) as my Cox Tee Dee .09 that has the Cox carb.
Though, it transitions better from idle to high and back with the Enya carb over the Cox carb.