Shiny new engine

Our rototiller is 38 years old.  It's a beast, and a new one just like it is about $2500, so it's important to keep ours running.  For starters, it was given to us by Dan's parents, so we can't argue with the purchase price.  Dan had to do some initial maintenance when we first got it, but fairly minimal.  This year, Dan pulled it out of the garage and it started on the first pull.  Woohoo!  However, he would get half way down a garden row and it would start spitting and sputtering.  He tinkered with it and determined the engine was shot.  Sigh!  After much Internet searching, Dan found the engine he wanted and installed it in a matter of minutes.  It looks slightly 'modern' compared to the rest of the tiller though...