I found an easy way to repair your broken heat tube. Get an ⅛" pop rivet that's ½ to ¾" long. Cut the " bulb " end off with a fine hacksaw. Pull the nail out of the rivet. This rivet can now be gently tapped half its length into the existing hole in the exhaust manifold and the broken tube will snugly fit over the other portion! Quick, simple fix! No drilling or anything else but a little clean up at the pipe and manifold ends. The downside is that your tube has to be relatively good, other than where it snapped off at the manifold.
I like this! Very simple yet effective. They usually break off right at the manifold, so most should have no problem fixing their tube via this method.
The hole in the pop rivet seems small, but flows plenty of air to the choke! If it ever clogs up, a small drill bit will open it right back up! I did this to mine over a year ago and haven't had to touch it since.
