I have a Stark backpack blower. Ran for an hour perfect then started bogging down. I shut it off. Now the pull cord won't pull more than a couple inches. How come?

SOURCE: blower wont run at full throttle

Start with the spark plug it is the easiest.

But sounds like the carbourator is dirty, Probably fouled with old gas varnish. When it is idling give it a little throttle, flip the choke on and then full throttle. If it goes full throttle and doesn't conk out, it is a fuel issue.

Good Luck

SOURCE: My Homelite backpack leaf blower only idles. when

Is the new gas some you just mixed up from the gas station or is from the can in the garage? If it is indeed fresh then you are looking at needing the carburetor adjusted. Sorry you can not do it yourself, The epa only allows qualified technician to adjust them. Plus the tool to do so are not available to the general public.
HTH
Good Day.

SOURCE: Ryobi backpack blower will run all day with choke

Thats a lean condition. Check fuel lines and fuel filter. If the fuel ilnes are discolored or stiff or really super mushy, If the fuel filter has become detatched from the fuel line then the fuel lines need to be replaced.
If the carb can be adjusted you can try to adjust but its likely that the carb should be rebuilt with new diaghrams and gaskets.
Adjust by turning the low speed screw out ( counterclockwise) 1/2 a turn. The low speed screw is always the one closest to the motor and usually marked on the carb body with an 'L'. When you richen a motor up the idle will drop so you will probably have to turn the idle screw in 1/2 a turn. 1 and 1/2 turns out from light bottom is standard starting point ( 2 turns for poulan products). If you get more than 3 and 1/2 turns out on the low speed screw or if turning the screw has little or no effect then the carb should be rebuilt.

SOURCE: bogs down at full thouldel tryed to adjust carberator

Hi
This is either a clogged muffler or carb. Take the off and see if it will rev. If not you need to clean carb and install a carb repair kit. Do not run long with muffler off.
Sam

SOURCE: BR340 Stihl backpack blower. Pull cord hard to

make sure unit is not flooded. some units may be hard to pull because they dont have a relief for the compression.