I was given a Yard Man mower that wouldn't run, carburetor was beyond repair. Engine is model 122T02-0377-B2. Ordered carburetor #799872 ( aftermarket, not OEM ). It will start and run fine with a shot of starting fluid but won't start again without another shot. Replaced primer bulb, cleaned the air passage and screen in the filter box. Is the throttle valve supposed to be fully open when starting and is the primer the only thing that chokes it?