Carburetor Repairs

 When I started working on the Carburetor I got out my NA-S3A1 manuals and looked up the carb. part number only to find I didn't have a spec sheet for P/N 380167-2.  I had a sheet for a 380167-4 but was it the sheet to use for my carb.  The Continental P/N 40590 on the carb. is the correct number so the question was what is the correct Bendix (formerly Stromberg) data sheet to use.  After searching the web and finding no other books than those I had, we finally figured out that the dash number is the issue number of the Parts List/Setting Specifications.  The correct sheet to use is the latest issue, except for 2 sheets where the change is to allow (not require) moving the Idle Bleed Hole.  Therefore I'm setting up the carburetor as 380167-4 and have re-stamped the dash number to reflect this.  I have no ability to flow test the carb. so the work can only be signed off as Inspected and Repaired As Needed (IRAN) not Overhauled.  Everything else is easy to comply with in the manual. I haven't researched all the C-90 carbs. on this list.

 At this point everything is cleaned, inspected and the paint has baked in the sun for about 6 hours.  The fit of all the used parts are still within new limits so that's good news.  There were some slight scratches on the mixture control plates and a burr.  I cleaned up the burr and lightly lapped the mating surfaces with crocus cloth and cutting oil on a glass plate.  They cleaned up well and should seal much better.  I also burnished a little of the Molykote G-n paste, as done on the tappet ends and cam lobes, into the mating faces of the plates.  I then rubbed them together to work it in in better.  It was surprising how much smoother they moved.

I have everything ready to install the float, to set the fuel level but this is as far as I can go for now.  The slot in the new needle valve is undersized so much it will not even fit on the pin on the float.  The slot is supposed to be .128" - .130".  This one measures .1245". The pin on the float measures .1255", well within the .124" - .126" limits.  I'll get with Fresno Airparts and sort it out.

I've got lots of other things to work on.