There were a couple of different Fox carbs for their larger engines. Most used the early carb that had a low speed needle in addition to the typical high speed needle and no one knows what to do with that. They got away from that much later on, but I don't know that those were much better. I can't help you on the Kazakstan issue , though!
   Type at you later,
  Dan McEntee

   There were a couple of different Fox carbs for their larger engines. Most used the early carb that had a low speed needle in addition to the typical high speed needle and no one knows what to do with that. They got away from that much later on, but I don't know that those were much better. I can't help you on the Kazakstan issue , though!
   Type at you later,
  Dan McEntee

    I'm thinking that's the earlier carb. Maybe check out the Scepter Flite web site and see what they have. There was a guy in a local R/C that really understood Fox carbs and some how used a monometer to set the needle for proper to get them in the ball park, and then would adjust them for final run for people. At that time period, the .40 was considered the most powerful .40 on the market, if you could understand the carb and how to adjust it. If there was a major weather shift, you needed to know what to adjust for the temp changes and such. I never had to run one myself, and I think I may have a few carbs around here myself as I had a couple reworked by Lew Woolard for stunt. As I understand it, it's like any other carb. High speed needle is just for wide open throttle, and the low speed needle was just to get the transfer from idle to about 3/4 throttle. Is there an air adjustment screw on it? When OS came out with there easy to adjust carbs, that is what hurt Fox .40 sales.
  Type at you later,
    Dan McEntee

Thanks, I'll check out that website. As I mentioned earlier I did get the engine to run fine after a slightly extended break in. You are entirely correct about OS. My first was a 40FSR and that was an amazing motor. Absolutely no problems with it on a Kadet until I peeled the wing off in a 12G pullout and the fuse went full cruise missile into the ground and it ripped the entire carb and carb boss off. Then the idle was hard to adjust.
I'm a bit of a Fox fan as the Fox 35 was the first engine as a kid that would start and run well. Then in my early combat days in the 80's got some factory support and even bought a 55 gallon drum of Duke's Fuel for my team for practice.
And I'm cheating a bit as I did get a new OS 40ASK in case the Fox does't pan out. Nice motor but with the new square styling it is butt ugly.

http://www.flitelinesolutions.com/project4.html       I always found this helpful.