I have been putting together old junked out partners the last couple of days ,stuff that I have bought not running for 1 reason or another.The saw I am stumped about is a 500 I bought it for $20.00 all apart in a bag.The guy said his saw shop told him it just was not worth fixing ?so. I thought 20 bucks was cheep enough fot the parts so i bought it.I got looking at it today and decided to see if I could see what was wrong with it. It was really packed with oily saw dust everywhere. So I took the Flywheel off the base cleaned behind it and around the coil ,it was so packed full it was a wonder the coil could send electricity between it and the wheel.I put the jug and Piston back on,... the base gasket was a little rough but I cleaned it as best as it could be and put her together. I put the carb back on after I blew it out a little but i have to say that was the cleanest carb inside I have ever seen. Hooked up a spark plug and pulled it over and viola Bright Blue spark. I thought this will run I'll just squirt a little gas in the plug and carb. Well I did that and all it did was put put put but it would not run. I gave it some thought and figured that the base might be flooded so I pulled the plug and pulled her over 50 or so times. Still nothing, so I figured the base gasket might be the trouble but I could not figure out why the gas in the cylinder would not fire? So I pulled the jug and Piston changed them out and put some permatex on top of the old gasket and put her back together. Tried just starting as normal and no go so I put some gas in the cylinder and it started for maybe 5 sec. so I repeted it with a little more gas and this time I figured if it statred I would use my thumb to choke it to keep it running.Well it started and when I tried to put my thumb over the carb it accidently touched the plug wire and WOW that baby has some serious electricity ,man numbed my arm for 5 min. but putting more gas in the carb and cylinder again it still will not even run 5 sec again so I am lost dont know what to do next any suggestions?