ok i have a stock 305 bottom half with a 490lift cam with a 286 duration and 1967 327 heads 64cc. the car was runnin great with the stock intake and quadrajunk carb but i changed the intake to an edelbrok performer and a holley 750 carb (i know its big but it should still at least try to start better.)with 64 jets in front and 66 in back. the timing is right ive checked it a thousand times and the floats are set right also on the carb. when crankin over it doesnt want to do any thing at all unless i give it a **** load of gas and even then it just sputters. occasionally pops and when i get to carried away a little bit of fire in the carb can anyone tell me why this thing wont start.

 

what about the ignition itself? Do you have a good spark?

 

yes good spark everything is still great other than since i changed the intake and carb now it wont start but it is also crankin over rather sluggish than usual but the battery is 100% charged i have a charger/ tester. i have tried 4 diff carbs. 3 of them i know were 750cfm but the last one not sure because the part number isnt on holley's website even though i know for a fact its a holley.

 

Spray some starting fluid down the carb throat. If she fires up, you know the carb is at fault. If that doesnt work, Id start looking at timing, ignition and dont leave out choke issues.

BTW, 750 CFM is WAY to big for that engine. Check the plugs. Are you flooding her?

Its good to know Im not the only one who has nightmares after what should be a textbook bolt on operation..............

 

hey im gettin fuel no need for starting fluid. and yeah i know 750 is too big but hey i should get somethin and timing is dead on and spark is good. oh and there isnt a choke on it.

 

Yes you are getting fuel but did you know you need the correct air to fuel ratio in order for gas to actually ignite.....and with no choke on it could be the problem try pushing the flap down and starting it....and for the slugishness try check your starter

 

Don't take offense at this, but are you absolutely certain that the timing is correct? What you are describing sounds like your distributor is 180 degrees off. I experienced this when I swapped the intake manifold on my first car I ever owned. It actually ran, barely, but backfired badly and wold occasionally ignite gas in the carb. I don't remember if the starter was sluggish (after all it was 20 years ago). Are you sure that you have #1 firing at the top of the compression stroke and not the top of the exhaust stroke?

 

i even turned the distributer 180 just to make sure and still same problem. but thanks and also for the other response i know about air to fuel ratio and reace carbs dont have chokes and if i dont give it any gas or a little bit it does nothing until i give it a **** load of gas and then it sputters and pops and the carb catches fire. even with the stock quad on it because i just tried it with that. so ive tried the distributer both ways, 5 diff carbs now with little gas no gas and alot of gas. no offense taken to suggestions though by the way but if you are to respond make sure you read my messages. i pretty much explain everything. that goes for everybody. but thanks for the help. any other ideas.

 

Way to much fuel! your drowning the little guy, that post about air/fuel mixture is dead on. I had a new 350 target master engine, and installed a performer manifold with a 750 holley, and she started hard, when she started, and she belched fire alot. pull that 750cfm off, that is the holley double pumper correct front and rear floats. Ok if your dead set on that carb, try putting a fuel metering gauge on the line before the carb and crank down the fuel being delivered to the floats. And see if that helps, it should.

 

if you had read i pulled the 750 off and put on a 600 the car starts now but it wasnt because i over tightened the valves. now the problem is spittin and poppin and the valves wont stay ajusted which was the original reason for the overtightening.