When is it time to rebuild the carb?

[stihl025]

Is there a set amount of time, age of the saw, use factors, etc. when the carb should be rebuilt?

My 025 was slightly modded with the DIY muffler mod, carb was readjusted from my dealer for proper mixture. Ran pretty good all last year. This year, saw still runs good for the most part, but if I set it down for a moment and go to pick it back up, the upward motion causes the saw to die out. It doesn't just fire right back up, it sometimes takes a few pulls, or even a quick choke. The saw is 11 years old this years and still running strong, but never has had a rebuild or any major work. Any thoughts???

 

[Lakeside53]

Maybe... or it might be just set to rich (L)... Rich idle causes pooling of gas in the crankcase or inlet boot, and sudden motion floods the saw.

 

[Fish]

The diaphrams are likely stiff, but the fuel line likely has cracks in it.