hello, thanks in advance for any help. i seem to be hitting a wall here. im trying to get an old husqvarna 257 saw up and running again after several years downtime. i took the carb totally apart and cleaned it, changed the plug and gas. after i got it back together it now starts right up (it did not at all this morning) so now im trying to tune it and not having much luck so im hoping someone here can help.

1.i set both screws to the factory setting, one full turn out.

2. i started it up and let it run for a few min to warm up.

3. it seemed to be idling nicely so i gave it some gas. it reved nice and high for maybe 10 sec then died. i repeted this same thing a few times, each time it died after a few sec at high speed.

4. now it wont start.

what steps to i need to go through to a. get it to start again and b. tuned so it will run at high speed.

thanks!