hi, any body know how this valving from a pressure pump goes back together ?? i forgot to take note....... thansk, mark . k[ATTACH]59372[/ATTACH][ATTACH]59372[/ATTACH]

I have a Murray M2510 gas trimmer that I've had for I think almost 3 years now. I already replaced the carburetor once. Sometime over the summer it has developed an issue where it doesn't want to stay running unless you're giving it throttle. To break it down a little, this is what it does: You can prime it, put it on full choke, pull it a couple times to where it fires a little, then put it on half choke and start it (which is what I normally do to start it). After being started, if you don't give it any throttle it will run for maybe 30 seconds or so (often less) and then shut off. After it shuts off, you can't just re-start it on half choke, you have to put the choke on full and repeat the starting procedure (minus the priming) and this is the case no matter how long you've had it running. Other than this issue it runs really good. What do I need to look at to fix this?