Drone Diesel modified for throttle control

A friend (Jack) asked me "if" I could adapt a carburetor onto his Drone diesel?
Two years ago, I was able to adapt a muffler onto the Drone for Jack as where he flies "all" engines are required to have mufflers/silencers.

Well, I told Jack I give it a try.
First thing was to measure the i.d. size of the Drone's venturi. It was just shy of .250" ( less than1/4") at .231 inches.
As the i.d. was a little rough I used an adjustable reamer and reamed the venturi to exactly .250".
That cleaned up the venturi bore to a nice surface finish compared to a rough sand cast finish with black paint.

And while at it, I cleaned up the top face of the venturi so that the face was perpendicular to the venturi bore.



As I was already working on some Enya .09-II engines that were for U-control and I was modifying them to fit throttle valve (carburetors) to them by using Enya .09-III carburetors. But the Enya .09-III carburetor dia.is .321" (about 8mm) so I have been turning the stem part that fits into the venturi down to .250" to fit into the Enya .09 / Enya .09-II engines.
With the venturi on the Enya .09 and Enya .09-II at 1/4" in diameter I tried one of those carburetors into the Drone venturi.

It was a good fit, except the stem was short.
So, I ordered from MECOA the Enya .15/19 carburetor with the long stem.




As luck would have it, the screw holes on the Enya carb were at the exact same length (location) as the original needle valve location on the venturi, so no modifications or extra drilling was necessary.

All I have to do is to turn the carb stem down from the 8mm dia. to the 1/4" diameter.
Below are the before and after of the turning of the carb stem.




After that was done, I made some carburetor gaskets from the thicker Enya gasket sheet (from Bob Brooks) using my punch plug/die for a good fit on the carb.



Now Jack has a throttle for his Drone diesel.
And he can have the throttle arm on either the right side or left side of the engine?










As this was an easy job for once, and it only took less than 3 hours to complete.