Won't start back up

Sounds typically like a fueling problem 'starvation' check the fuel system from the fuel filter, fuel lines, and carb. could possibly need carb cleaning and gaskets replacing or could be a plugged fuel filter or split in a fuel line. I've attached the breakdown manual for you.
http://www.mediafire.com/view/7jkzri5m6fyk4fi

check line for leak have u changed fuel filter inside tank

If the fuel line and filter are in good shape then it will probably need the carb rebuilt or replaced. Check the fuel line first. The ethanol in gas eats these up badly.

Hi the fuel pump is located under the back seats , and under the flap of carpet is a round disc with three screws ! And underneath that you will find a big plastic ring which holds the fuel pump !! They are easy to take out and replace plug and play really ;) Disconnect the battery !! First and be careful please !! Good luck

I hope you cleaned the fuel line so there weren't any cuttings in the line? I would have probably used a small round file to clean burrs inside metal line. I don't know liter size of engine? I looked at 5.0L--carbed engine--fuel pressure 5--7 psi.
If your fuel injected, the pressure is a lot higher.

there is pick up screen in the tank or sometimes called a sock . steel or plastic mesh remove it..

Remove plug and clean/replace. also check in the tank for a filter on the end of the fuel line.
Ground the plug of the body of the saw and stry to start to see if you are getting a nice healty spark. If you tank ran dry then you may have contaminated your plug.

Check the fuel lines for hardness, cracking, splitting, or end rot. Check the muffler for plugging. Check the carburetor fasteners for tightness. Are you using fresh fuel mix? If the carburetor jets have been adjusted, try turning both CW to stops (lightly) then back out each CCW 1-1/2 turns. Engine should start and run--allow to warm up. Pull the throttle full on, and adjust H needle CW until the engine starts to speed up, but still 4-strokes. Proper adjustment is when the engine 4-strokes, but immediately 2-strokes when cutting. Let idle and adjust L CW for fairly smooth running, but still allows the engine to 'follow the throttle'. Hope this helps!

Make sure you are using fresh fuel mix (50:1 ratio). Don't use boat motor oil in a saw--only modern synthetics made for saws. Always premix the oil and fuel thoroughly before adding to the saw. Check the fuel filter for plugging and the condition of all fuel lines, plus the primer bulb condition. Check all carburetor fasteners for tightness. Make sure the air filter and muffler are not plugged. If still no help, you may need to service the carburetor. For an excellent article on Walbro carburetors, go to: http://www.drystacked.com Pay particular attention to the placement of the lower diaphragm and the cover gasket--interchanging positions of them cause many headaches. Adjustment of the two jet screws require a special 'D' screwdriver which may necessitate a trip to a servicing dealer for adjustment. Hope this helps!

hi
if you have a good compression,a strong enough blue spark and carburetion for the fuel air mixture try priming the engine(put small amount of gas in the spark plug hole)then start the engine.If the engine runs only the gas you put inside the cilinder there is a carburetion problem to find and fix.
let me know regards savumihai71