The mailman just dropped off two great looking AP Wasps from the fine folks at Hobby People and at $29.95, what a deal!
Now what am I going to do, I want to use them as C/L engines and they have R/C carbs? Searching this site has turned up two possible solutions, I can substitute a TD .049 carb of which I don't have a spare or I can order an aftermarket venturi assembly from a fellow named Jan who's contact info seems to be a closely guarded secret; and I can't see him making and selling a custom carb. for less than the cost of the engine. What to do? Is there a DIY solution?
Yes there is, all the parts you need already exist or can easily be made. This is what I did:

1. (Examining the R/C carb., I noticed that it is of clever design. The rotating Barrel is retained by the Fuel Nipple which is screwed into both the Body and the Barrel. This arrangement forces the Barrel to move latterly when rotated so that coupled with the taper of the Needle Valve automatically adjusts the mixture at different throttle positions.)
**This mod can be done with the carb on the engine (I elected to remove the carb.)
**Remove the Fuel Nipple and the Barrel may be pulled out of the Body.
**Remove the Needle Valve and undo the nut holding the Detent Spring and Throttle Arm.
**Remove the Idle Stop Screw.

2. Using a 5/32" or #22 or 4mm drill bit drill out the threads in the Body as shown in the 1st photo.

3. Make a washer and spacer (see 2nd photo):
**Make a washer from the Throttle Arm by cutting off the arm (I used side cutters).
**Make a spacer by forming a length of 1/64" (.015")  or .020" music wire into a loop with an outside diameter the same as the Barrel.

4. The 3rd photo shows the exploded view of the parts ready for assembly and the 4th photo shows the unit assembled.
**The Nipple now slides into the Body and threads into the Barrel securely locking the Barrel in place.
**The Spacer is needed to center the venturi hole in the Barrel with the venturi hole in the Body.
**I elected to mill off all of the unneeded  material from the Body to make it lighter. This is not necessary.

5. The last photo shows the carb back on the engine ready to test. I will run it in this condition until it is broken in. I should get the rated full speed specifications listed by the manufacturer.

6. After break-in, I will "Hop-up" the engine (Geezer Mod #2). The venturi diameter of this carb is 3 mm (.118") but it is somewhat restricted by the orifice and needle valve. The stock TD venturi is .115" and is unrestricted. Jan's unrestricted venturi is .125". One should be able to drill out the Geezer modified carb to up to 4 mm (.156"). This is probably bigger than you would want to go for normal fuel draw but would probably work on pressure.

** THe really neat thing about this carb mod is that by simply loosening the Fuel Nipple, you can rotate the Barrel to adjust the venturi size to suit and then lock it in place again by tightening the Fuel Nipple........ cool!

7. I will post the results of all these modifications once it warms up here and I can run the engine out of doors... stay tuned!

Orv. the GizmoGeezer

Chuckling... looks like a lot of work where you might instead use a piece of music wire and just hold the carb open.    Besides when I am tired of the motor I figure there will be someone on Ebay who will buy it for their little RC plane if the carb is unmodified.    That said selling the carb on Ebay now would probably pay for the venturi assembly....
Bob

  Dan B I sent you a P/M...  Bootlegger

         Hello Rudi, wiring open the carb is a simple solution. In fact this is what all of us were doing prior to certain commercially made modifications. The hole in the carb only appears large, the barrel is necked down internally. The problem with the carb is the fits are poor. So many air leaks are there and all need to be addressed. The engine will run but it runs a lot better is some of these leaky situations are fixed. Ken