I have a Briggs 10t502 B1 0457 on my Troybilt lawn edger. It's a vertical shaft. It has been getting harder and harder to keep running. When I start it, I have to keep pushing the primer bulb to keep it running. Eventually, it will run on its own without priming. At first, I only had to push it a few extra times. Today, it took me about 15 minutes of pushing to get it to keep running. Removing the air filter doesn't seem to make any difference. Removing the gas cap doesn't help; I can see through the vent holes in the cap. The gas is fresh. Less than a month old with stabilizer added as soon as I got it.

It has taken most of the summer for it to go from running fine to its current state.

I've looked up the carb. There doesn't seem to really be anything much to replace but the whole carb. It's cheap too. Do you think that is my problem? Is there anything else I should check? Thanks for your help!