Spacebug-Style Crankshaft Repair

So last week I won this dead Thermal Hopper.
http://bit.ly/1fuMONt

It suffered from the all too common broken off threads on the crank. I wanted to bring it back to life.

Most would assume just replace the crank, but those are a rare commodity on their own. So I hatched a new plan. I had a small threaded rod I got from another engine that was the proper thread. So what now? Weld it. I clamped the rod and the crank(wrapped in electrical tape to protect the bearings) and put a small gap to assure good penetration and a couple zaps with a mig welder. Then I used a file to carefully true up the weld and make it more uniform.

Here's the results.

You care barely tell.

It's not perfect or beautiful, but it'll work.

Also ignore the incorrect head/cylinder. Just what it came with. But it's great to see it in one piece again!

So if you've got a broken one, don't fret. It can be saved!