We need to get more information, bill.
First, let's talk basics. Here is how you are supposed to start it:
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2013/11/full-2772-13382-stihl_fs120_trimmer_starting.png)
This does not sound exactly like what you said you have been doing. First, you have not confirmed that you have been setting the throttle to the start position, for both cold starts and hot starts. You would be very lucky to get the engine to start if you do not do that. Second, you have not been priming it to hot start it, but as I read the instructions, Stihl says you have to (which surprises me considerably - I've never done such a thing as prime a hot engine, but it is at least one of the things you need to try). Now, after doing exactly what Stihl says you should do:
1. Does it start easily from cold?
2. Does it do warm restarts easily?
3. Does it have a new spark plug?
4. Have you tried loosening the fuel cap, in case it is not venting properly?