ptxman

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Kind of an offbeat question, but if anyone happens to have this specific model# carb, I am trying to determine the venturi hole diameter in the rotating barrel before I try & buy one. If you could get a set of calipers in there & let me know please. According to OS the same carb may have been used on similar displacement engines, some of which may be on their way to being discontinued. But specifically its the model 21K I'm wondering about. Reason: I'm on the home stretch constructing a 5 cylinder radial. The carb prescribed on plans is long outdated, so looking for a current model replacement based on similar orfice/displacement combination.

706jim

Can't say about the carburetor, but your machine work looks lovely. Did anybody else notice the tiny chamfers on those counterbored holes?

ptxman

My Feedback: (2)

Thanks for the compliment. I've been machining on it somewhat sporadically for a few too many years now. Hoping this will be the final push & hopefully make some noise soon. The remaining fiddly item list is still quite long.

BTW I've since received some information from RC Japan. I'm actually not sure if OS is in between engine models which might explain some discrepancy between carb models. then to complicate matters, orifice diameter isn't really documented because most people are just trying to replace with correct PN. this doesn't factor the true open area with spray bar etc, just the hole size in the rotating barrel part.OS-23181200 (For 35AX) : 6.8 mm

OS-22582000 (For 25AX)：6.1 mm