Maxam As I have always followed your advice in the past, including buying the UMS 9-99 for my87inch Ziroli Stearman, I have decided to put in the OS carb using the CH adapter. I have several questions regarding the installation. I don't believe the stock choke assembly will work with it. I see that Chorner uses an Os choke valve. I find that Tower lists a choke valve as number LXCF23. Is that the correct one to use? No matter how I look at the set up it looks like getting to the LS mixture control will be difficult. I am thinking about setting it a little rich and relying on my on board ignition to keep thinks going at low RPM. Any tips on installing the OS carb and tuning this engine with it would be appreciated.

MY Stearman has flown quite well with the stock 9-99 with a 24X12 prop but could use more at the high end. I have to admit though that after 40 plus years of modeling my engine knowledge benefits greatly from this thread. The introduction of the radial has enhanced my modeling pleasure, but I would be lost without this thread.