Husqvarna 150bt Leaf Blower Running Leaner - Harder to Start

Blower is taking 3 - 5 pulls to start when it used to take 1-2. I pulled the spark plug and it has changed to very light shade of tan and was previously a darker shade, indicating a leaner mixture. There are air bubbles in the primer and takes 10x to remove most but not all bubbles. Primer does not appear to have any leaks.

A quick check of the fuel lines in the tank look OK, there is no obvious rot. Blower is 4 1/2 years old with 160 hrs. Should I just change out the primer bulb and fuel lines to eliminate possibility of small leak? Any other typical places to check this blower with a walbro wya79 carb?

 

Check the spark arrestor in the muffler. It may be partially clogged.

Also, make sure the fuel filter is attached to the end of the fuel line.