Homelite backpack blower, model ut08017g. Where can I get a manual?

SOURCE: carb adjustment tool

It is probably a star or a square head. You should be able to pick up at any auto parts store.
Hope this helps
Kurt

SOURCE: Echo backpack blower stops after 20 minutes

Make sure the fuel tank cap inlet valve is working properly, this will allow a vapor lock if it is not. Then check the fuel line in tank to make sure the pickup filter is not hung up in tank thereby allowing the fuel to get below the pickup. Also check the fuel line for holes. You can also try toro.com customer care, manuals and parts, type in model no. then get owners manual and see if in troubleshooting section it list this problem.

SOURCE: homelite Backpacker II leaf blower start fine then

have you checked air filter? the carb may need adjusting. locate the adjustment screw(s) , screw them all the way in then back out 1-1/2 turns. try to start the engine. then let me know what happens.

SOURCE: How do I adjust needle valves on a 25cc Homelite

Set the lowend & highend needles to about 1 3/4 to 2 turns each. Choke the carb or prime it, until the carb is wet. Fire up the engine and let it warm up. Let's set the topend first since it's the easier of the two. Go to full throttle. Adjust the topend needle for peak RPM. Leave it wide open for about a minute to see if it changes any. Should the engine go lean, open the lowend needle slightly, if this dosen't work... you will have to adjust the needle valve inside the carb.( I will explain this later) If the topend runs OK, then slowly pull the throttle down until the engine begins to "four cycle" hold the throttle there. Adjust the lowend needle until the "four cycling" barely stops. Now lower the throttle more until it "four cycles" again, and adjust the lowend again. Keep doing this until you reach full idle. Now, from full idle begin to throttle up until the engine starts to bog or hesitate. Open up the lowend needle just enough to eliminate the bog or hesitation.

http://tech.flygsw.org/walbro_tuneup.htm

hope this helps :)
if it does please vote

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.