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Discussion Starter · #1 · (Edited)
Hello guys got my cam swap done and am putting all my stuff back on tonight and will be setting timing etc tomorrow but need advice on where to tune my carburetor. Engine is 350 sbc I did have a comp big mutha cam with 243/257 @ 50 duration and it had 35 degrees of overlap and idled at 1300 rpm. I am now running a lunati voodoo hydraullic roller cam with only 231/239 @ 50 with only 15 degrees of overlap. I know this thing will not need a 1300 rpm idle to stay running etc and was hoping around a 900 to 1000 at the most.

My carburetor is a double pumper quick fuel q series carb with no choke tower and has four corner idle circuit metering. I know to have each butterfly with the same amount of fuel transfer slot on primary and secondary at .020 so it will idle. But what should I do to start to set a base tune on this thing. Do I turn each of the four idle control screws before I do anything with the primary and secondary idle screws while tuning it?
Also shold I take each idle mixture screw and screw them in all the way and turn them all out about 1 1/14 turns?
I was told to set you base idle with primary and secondary idle screws and go around and turn each idle mixture screws in one at a time till the engine wants to quit then turn back about a 1/4 turn on all four screws before I reset the primary and secondary screws is this correct? I have a vacuum gauge too and don't know what I should looke for by using it.

My carburetor was running extremly rich before I took out the big mutha thumper cam and will it still be rich or should I leave the carb as is or should I jet it down some. The jets in it are actually two sizes from what it came with. Icurrently have70 primary and 78 secondary jets in it right now. Thanks guys for any advice.
Eric
 

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Discussion Starter · #2 ·
Well I guess no advice so I will just take all of my ims screws and turn them all in and then back out 1 1/4 turn and start from there. Thanks to all who looked though.
Eric
 

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Discussion Starter · #4 ·
Yeah I have a vacuum gauge to hook up to it so I will adjust till I have the best vacuum then turn it back about a 1/8 to 1/4 turn. Thanks for the link apprecite it.
Eric
 

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Discussion Starter · #5 ·
Hello Fbird I do thank you for your advice. I have not got my timing light out yet but will do so tomorrow when I have more daylight. I got a nice 900 rpm idle now with my new lunati roller voodoo cam but I noticed when I took it out for a drive it was missing pretty bad and it would totally go flat then pick up when I got into it so I pulled out a plug and they are a white to gray color and I have a off idle stumble still but not as bad as before. I only went down two jet sizes from what cam with my quick fuel 650 double pump carb wich is the q series line. I would do it at all ponts of cruising till I got up too 4000 plus rpm then it went away some but not completly. I need to richen it up but I don't want to mess things up too much so should two jet sizes up on the primary be good to start off with? I am now at 70 primary and 78 secondary. Thanks for help it helped out a lot and my dad did not have to hardly do anything to get the thing running good.
Eric
 
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