It is also interchangeable with the HF 79cc if you have an old one around.
I have found it is real important to start both engines according to the manuals or the pull starts fail very quick. Gently turn over the engine then when you feel resistance, allow cord to rewind then a strong but not jerking pull.
From the manual;
4. Grip the Starter Handle of the Engine loosely and pull it
slowly several times to allow the gasoline to flow into the
Engine’s carburetor. Then pull the Starter Handle gently until
resistance is felt. Allow Cable to retract fully and then pull it
quickly. Repeat until the engine starts.
Note: Do not let the Starter Handle snap back against the
engine. Hold it as it recoils so it doesn't hit the engine