convert my lawnmower and tiller to propane

First, I’m going to try a simple method that I read about online. It involves removing the carburetor of whatever device you’re going to run on propane, and just running a length of copper tubing from a valve (like found on a propane torch) straight into the intake of the mower/tiller/whatever. This weekend, I picked up a cheap (<$10) propane torch body just to harvest the valve and the cylinder connection. But then I ran out of time. Maybe next weekend or some time this week after work. But what should I try first? The mower or the tiller? I’m done using the tiller for the season, so maybe I’ll do that.