useally if its that hard to start and its doing what you say its doing it will normally back fire and you will get a flame coming up out of the carb.i would definately pull the carb top off and have a look,ya never know just because there rebuilt doesn,t always mean there done right.i had to go through three rebuilt carbs to finally get a good one.i use to rebuild alot of carbs in my day.i have also seen where the main carb gasket dosen,t seal the upper part of the carb and the main base properly and cause fuel to get suck down the venturi and cause all kinds of issues.

 

brand new edelbrock 1406. it backfires occasionally. usually always puffs smoke but wont start for an hour or so.

 

Sounds like the valves are getting stuck open. How many miles are on the motor? Is the motor overhauled? Bored out?

 

Sorry, forgot to post an update this morning , I went back to advance and exchanged the edelbrock, slapped ot on, and had the same problem. On a whim i hooked up my boat fuel tank to her and strapped it to the roof for gravity feed right to the carb. Damn thing started up and ran smoother than it ever has. Let it drain the little 2 gallon tank, re filled it , figured id try plowing my driveway. Ran fine the entire 15 minutes. as long as i didnt give it too much gas (gravity feed didn't provide much pressure. ) it would keep up. So i figured bad fuel pump . Exchanged it. Hooked the new one in (those damn pushrods are a pita)and cranked her up. Ran for a few seconds, but once the fuel bowl was empty, it died. Clear fuel filter still full, i was puzzled. Then it hit me, my fuel line going to carb was drooping into a U shape with the filter at the bottom, so even if i didnt have fuel, it was full. Checked the main tank with a stick and it was nearly full. Blew out the lines with compressed air as suggested by my coworker, and wallah. It started right up. Turns out the ppickup in the tank keeps clogging.. man do I feel stupid.

 

Thats great you found your probelm,some times its easy to over look the simplest things that cause the most agrivation.its nice of you to post your find because some people don,t bother replying back.

 

Thanks for posting your fix!! Makes this a valuable thread for future reference! Great job trouble shooting BTW.