Broken prop screw Pee Wee .020

Left hand drill bit works if it’s not rusted tight. Get it centered and should catch and turn it out as it drills. I got a set at Harbor Freight.

Yep!...heat, PB Blaster,left hand drill bit, thread extracter.

...also, grab a loupe or whatever, and inspect where the
splines meet the crank. In fact, if you get the stud out,
there's a chance the spline section will fall away.
That's if the break was caused by a crash.
Bob

One more thing I would add, and that would be to purchase a:
CENTER DRILL COUNTERSINK BIT TOOLING SET.

It will not wonder like a drill bit would.
Recently, I removed all four screws from a Golden Bee crankcase using the #1 center drill bit.
The original owner of the Golden Bee used epoxy on the threads and all the bolts sheared off even with the crank housing.

Start the hole with the center drill bit, then change it out to the left handed drill.

Here is the web page for the center drill bits:

https://www.amazon.com/Naiyong-Countersink-Contained-Stainless-Metal%EF%BC%8CCopper/dp/B07GTDSCLY/ref=pd_sbs_328_3/132-2307981-3904247?_encoding=UTF8&pd_rd_i=B07GTDSCLY&pd_rd_r=05cdf2a8-6348-44c3-8ba2-d168f4436786&pd_rd_w=gxqgj&pd_rd_wg=qTdlP&pf_rd_p=ed1e2146-ecfe-435e-b3b5-d79fa072fd58&pf_rd_r=YTXYJBN3QZZS1XM1K65J&psc=1&refRID=YTXYJBN3QZZS1XM1K65J

They are good to have for any reason for drilling a hole where you don't want the drill walking before the hole is started.
The "gold" TIN coated ones will last longer. My go to center drill bit is the #1, which is the smallest for working on the Cox, or any model engines.

I once purchased a RR-1 for cheap with a broken prop screw in the crank. It was easy to drill out with a no. 38 hss drill bit as it won't cut the hardened internal threads of the crank. I then used a 5-40 tap to clean out the remaining material. Not sure about the size of the .020 prop screw.

coxaddict wrote:I once purchased a RR-1 for cheap with a broken prop screw in the crank. It was easy to drill out with a no. 38 hss drill bit as it won't  cut the hardened  internal threads of the crank. I then used a 5-40 tap to clean out the remaining material.  Not sure about the size of the .020 prop screw.  

3-48 is the .020 prop screw size.

Thanks Jason
Have a Happy New Year 2021!