Are you getting spark after it dies? IF not it maybe the kill switch or ignition parts that are bad or intermittent? I would also check the kill switch make sure it's good?

Does it hit off carb. cleaner when it won't start (by spraying 2 second blast directly down the carb. venturi or removing the spark plug and spraying 1 second bast directly into the comb. chamber. IF so, when you get it to run and pull the throttle can you see gas itomizting from the fuel manifold that has the mid and high speed gas port?

Last thought would be if it's getting spark when it dies and it will run off carb. cleaner till it runs out of cleaner you sparyed in. I would say you've either got vacuum leak (internal in the carb., at the intake manifold or at the jug where it held on at the crank case (usually 3 or 4 screws) or carb. diagram installed backwards especially on the needle and set side or internal passage plugged in the carb. or through the carb base to the crankcase.

IF this didn't spark some ideas then I would got to Zamacarb.com or walbro.com and study the troubleshoot trees see if that may help?

Does the muffler have a spark arrester screen and is it clean? Is there carbon in the exhaust port?

I will be sure to try both of those things and get back to you with the results. As far as the muffler I replaced it because I also thought that could be the issue.

check your fuel line for cracks. Also make sure your carb is adjusted correctly. Also make sure you don't have any leaks around the seals you replaced. Sounds like you have a lean condition.

Is there a special tool required for adjusting the carb (lean/rich)? Its a craftsman weedwacker. What is the best way to ensure the carb is adjusted correctly?

rcmoser - Here some answers to your questions:

1) Yes I am getting spark after it dies because if I wait just a bit I can get it to start again.

2) I began by using the choke each time after it dies until that no longer worked. Then I disengage the choke and it would start. I would do this until that no longer worked. Then I sprayed in carb cleaner. It did hit off the carb cleaner for a short period but I saw no itomizing anywhere.

I do see air in the lines. Perhaps there is a crack somewhere. I think I'll start by replacing those first.

What sort of tool is used to adjust the carb? It does not seem to be any typical head. It actually looks like it will require a female end to turn it.

Probably need spline wrench. You could use needle nose pliers. Some get the hi/lo screws out and cut screwdriver slot so you can use screwdriver to adjust. I would mark them first to see if you can acutally move them and for reference where you started.

Does this model have primer button? if so it maybe cracked. If you fuel lines or primer button have cracks it will cause fuel not to be pulled up to the carb. I would suggest you just replace the fuel lines and clean or replace the filter that at the bottom of the tank connected to the fuel line. It will take awhile to get the air out of them and fuel to start pulling up and through the carb. so you may have to prime with carb. cleaner several times.

I replaced the tubes and didn't see a change so I decided to pull the high and low screws out (with tiny pliers). In the past I was unable to move them back and forth very easily because it requires a special tool. Once I pulled them I cut a groove in each one and "presto" I could adjust them with a screw driver. After a little adjustment here and there it seems to been running pretty well.