ms180 No impulse line?

[Jed1124]

Just like the title says I had the carby off a ms180 today that was dying as soon as the choke was kicked off. My first thought was cracked impulse as the saw is about 10 years old w/no flippy caps. Pull the cover off take off the two carb nuts and try to pull off the carb with the choke linkage all in the way (bad design) and no impulse line. Where does this thing get pulse from? Is it the circular opening above the choke with the o-ring? Anyhow I think I found the problem as I shined a light in the tank and can see the fuel line is collapsed right where it exits the tank. Just has me scratching my head about that line.

 

[ncfarmboy]

The impulse line is in the carb. There is a port in the bottom center of carb ( intake boot side) that lines up with the hole in the intake boot (also bottom center). Impulse system is the same on the 021-025, MS210-250. The carbs from those models will work on the MS170-180.
Shep

 

[Jed1124]

thanks for the response!