When the squeeze bulb makes the motor run better, I immediately suspect the fuel pump. Sometimes blowing some air through it(gently)can remove some stuff holding a valve open inside. It might be time to open up the fuel pump and see if the rubber parts are OK. Some of the older pumps need replacing because they aren't supported with rebuild parts. The new-style small square pump is specified to replace those older pumps on the smaller engines. Some people think nothing of throwing their old, failed parts on ebay to offset the money they had to shell out to replace them. If you already have the small square pump, it is supported. The kit comes with good instructions. You will benefit from making a jig to hold the pump while working on it. A board with two large nails driven straight through will work. Space the nails so the pump body slides over through two opposite bolt holes. Make notes or take pictures of everything as you take it apart. It has to go back the same way. If someone already took it apart then you have to check their work. Use the factory book. New pumps are sooo expensive, I hate when that's the last resort.