starter switch. engine still sputtering 9N

OFF OBVIOUSLY 0

can you blow air in the fuel line to clean it or will it damage parts in the carb?

As to blowing out the fuel line. That would just move around any dirt/crud in the filters and tank.
Better to remove the filters and clean or replace.
Blowing into the carb intake line might just jam crud tighter into the float valve and might make it not seal properly (not good).

Roger in Michigan

BE SAFE, engine cold, and shut off, use a catch bucket, and have a fire extinguisher at hand....

To check for gas flow to, and into the carburetor, remove the pipe plug from the bottom of the float bowl. There will be an initial quick flow of the 1/2 cup, or so, of gas in the float bowl, then flow will slow down to the amount that can pass through the three fuel system screens, and the inlet valve needle and seat.

The flow should remain steady. I can't tell you an exact amount per minute, but it must be enough to sustain the needs of the engine (IF it were running).

If the flow is real puny, at least one of the three fuel sytem screens is likely plugged, or there is a restriction in the fuel filter head/valve.

Here's a link to a past post, picturing all 3 screens that need to be present, and CLEAN:

• Screens