I've converted an Echo chainsaw engine (which ran fine in the saw), but now will start but not continue to run. *My question is the chainsaw has what looks like a primer bulb, but is says purge valve on the saw. *Do I need to hook this purge valve up to the carb to run. *It has a Walbro carb, but it doesn't look like the carb off a string trimmer.

Purge valve, primer bulb, same thing. It just pulls gas through the carb to fill it for initial starting and we normally don't use it on airplanes. Block off the fitting for the primer bulb, and just run the fuel inlet on the carb to your fuel tank. The fuel inlet on the carb is the one closest to the cast metal cover on the carb with one screw in it. That's the fuel pump. Then choke it, flip until you see fuel getting to the carb, and you should be good to go.

AV8TOR