ariens mulch master wont stay running. priming bulb?

[aedude006]

I got an Ariens Mulchmaster at a rummage sale for 10$ that doesn't stay running. If I hold slight pressure on the priming bulb (not actually priming it) the lawn mower will stay running. If I do not, it dies quickly after starting. Is there some sort of vacuum that runs through this bulb where there might be a crack in the bulb I'm sealing? recommendations? Thanks for your time

 

[Rivets]

Time to clean and rebuild carb. Your unit is running lean and the extra vacuum you cause by plugging primer vent is allowing the fuel to be pulled farther to keep engine running. When you set the float level, set it a little on the rich side.

 

[sidemouse]

Yes, primer bulbs most certainly can crack and leak air, plus it's a cheap and relatively easy fix.