Painted Parts, Spark Plugs & Propeller

 While I wait for the needle for the carburetor, the air box is painted and baked in the sun.  They came out nice.

 I bought a new set of 4 Champion spark plugs, but I also have a used set of 4 plugs for the other magneto.  The problem was I could not identify who made them or whether they were legal to use on this engine.  Three of them were to rusty to read the markings but obviously identical.  The fourth on had markings still but there was no way to read them.  After Caleb helped make sure they all are working I had an idea on how to figure out the numbers. I lightly filed the flats with the numbers until they were just readable.  It became obvious the one flat had "BG" on it.  Sure enough BG was on the TC data sheet (E-233) and the Continental service letter on spark plugs (SIL 03-2B).  Careful filing of the flat with the number revealed 706SR.  I have no idea what the SR stands for but the plug is on the data sheet so I've cleaned them up and they're ready to install.  I've highlighted the numbers here so they show up better.

I didn't know anything about BG plugs but it turns out they've been in business since 1918 and still make plugs and igniters and such.  They were big into aircraft plugs in the 30's and 40's.

While Caleb helped check the plugs I found out he needed a propeller for the C-150.  I came back here and carefully checked the numbers on the prop for the Fly Baby.  It turns out it's a McCauley 1B90-CM which is the right prop for the C-140.  It's still 71 inches long and was re-pitched to 44 inches so as long as the static RPM is within limits I have a prop for the plane.  I wanted a climb prop so this is perfect.  I always wanted to make a wood prop for the Fly Baby so I'm thrilled.