homelite super ez

Recently acquired a red and white Homelite Super EZ Automatic. I believe it is a 1974??? Anyways, the chain on it barely fits with the tensioner turned all the way out. So I compared it with a 3/8 chain I have off my Mac since they are both 59 DL. The Mac chain is 3/8 050 gauge while this chain...

Can someone tell me which carburetor I have on my Homelite Super EZ Automatic? It has the numbers 21-109 on the top of the carb. Are there additional numbers I should be looking for? I was able to find the Service Manual. It says that it should be a Walbro HDC carburetor in the Super EZ. I...