Just wanted to throw a plug out there.
I have an Echo leaf blower, maybe 10 years old, been getting harder to start over the years. I was getting ready to order a $25 replacement carb, no big deal. Yesterday, after pulling it 10 times, playing with the choke, cursing, etc, it started. I saw a can of Seafoam on my shelf, said what the heck, but a small amount in the blower tank, maybe 1 oz, and used it. Today, in the garage, saw my blower, went over, 2 primes, started first pull, just like the old days.