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Holly 650 double pumper trouble? #1446428 06/02/13 08:04 PM 06/02/13 08:04 PM
Joined: Dec 2003 Posts: 1,747 PA P plumcrazycuda OP top fuel
plumcrazycuda OP top fuel P Joined: Dec 2003 Posts: 1,747 PA	I just bought this carb and it is used but looks good. I put it on the car and it wants to run but can't get it to idle. I got a vac gauge and some how I am loosing vacuum when I get it down around 1k. anyone have any idea what is going on with the carb?

Re: Holly 650 double pumper trouble? [Re: plumcrazycuda] #1446429 06/02/13 09:06 PM 06/02/13 09:06 PM
Joined: Dec 2003 Posts: 1,747 PA P plumcrazycuda OP top fuel
plumcrazycuda OP top fuel P Joined: Dec 2003 Posts: 1,747 PA	I figured it out. I had the large vacuum port unblocked.I Plugged it and it idles good now.

Re: Holly 650 double pumper trouble? [Re: plumcrazycuda] #1446430 06/02/13 10:07 PM 06/02/13 10:07 PM
Joined: Nov 2004 Posts: 2,119 sc T tjmarcus1 top fuel
tjmarcus1 top fuel T Joined: Nov 2004 Posts: 2,119 sc	I would have thought you could hear a huge vac leak?

Re: Holly 650 double pumper trouble? [Re: tjmarcus1] #1446431 06/02/13 10:31 PM 06/02/13 10:31 PM
Joined: Oct 2007 Posts: 485 Raleigh, NC J j.mcconnell mopar
j.mcconnell mopar J Joined: Oct 2007 Posts: 485 Raleigh, NC	Any ideas on something other than the port being unblocked? I have a similar situation (bad, unsteady idle) and all of the ports on the baseplate are plugged. While measuring the vacuum at idle, I can unplug the gauge to create a vacuum leak and it doesn't make it idle any worse. Waved a propane torch and sprayed ether all over it with nothing really stood out

Re: Holly 650 double pumper trouble? [Re: j.mcconnell] #1446432 06/02/13 10:42 PM 06/02/13 10:42 PM
Joined: Feb 2006 Posts: 686 PA A ajcasini mopar
ajcasini mopar A Joined: Feb 2006 Posts: 686 PA	How far open are the throttle blades? How many turns on 4 corner idle screws? You may be too rich at idle and causing you to open throttle blades too far which is idling off the man circuit not the idle circuit. Make sure your throttle blades are only open enough to make a square out of the transfer slots.

Re: Holly 650 double pumper trouble? [Re: j.mcconnell] #1446433 06/02/13 10:51 PM 06/02/13 10:51 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Whats your base timing at... make sure you have enough timing first thing

Re: Holly 650 double pumper trouble? [Re: MR_P_BODY] #1446434 06/02/13 11:19 PM 06/02/13 11:19 PM
Joined: Dec 2003 Posts: 1,747 PA P plumcrazycuda OP top fuel
plumcrazycuda OP top fuel P Joined: Dec 2003 Posts: 1,747 PA	With open headers I couldn't hear. As far as the timing I have 34 degrees at about 2800 rpm.I may have to jet it down some. The guy I bought it off of told me it was on a 440. It don't seem to be running rich but I was just happy to get a idle at this point!

Re: Holly 650 double pumper trouble? [Re: MR_P_BODY] #1446435 06/02/13 11:24 PM 06/02/13 11:24 PM
Joined: Oct 2007 Posts: 485 Raleigh, NC J j.mcconnell mopar
j.mcconnell mopar J Joined: Oct 2007 Posts: 485 Raleigh, NC	Saturday I removed the carb and squared up the transfer slots and set the idle screws at 1.25 turns out from all the way in. Initial timing was 15 degrees. The car would not idle like that. I had to screw in the idle speed screw about 4 turns to keep it alive. At that point I could still kill the engine by screwing in the idle mixture screws. I upped the initial timing to 20-22 degrees with no real improvement. I have a lean burn distributor I was going to swap in but didn't have a rotor for it.

Re: Holly 650 double pumper trouble? [Re: j.mcconnell] #1446436 06/02/13 11:37 PM 06/02/13 11:37 PM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: Saturday I removed the carb and squared up the transfer slots and set the idle screws at 1.25 turns out from all the way in. Initial timing was 15 degrees. The car would not idle like that. I had to screw in the idle speed screw about 4 turns to keep it alive. At that point I could still kill the engine by screwing in the idle mixture screws. I upped the initial timing to 20-22 degrees with no real improvement. I have a lean burn distributor I was going to swap in but didn't have a rotor for it. If you squared the transfer slot, turn the mixture screws out some so you can turn the idle speed down.. once you get it down then slowly turn in each mixture screw till the rpm drops then back it out 1/8 to 1/4 turn... do each one while keeping the idle speed down... I would set your timing at 18 for the base timing... you may need to curve the dist so you dont get too much

Re: Holly 650 double pumper trouble? [Re: MR_P_BODY] #1446437 06/03/13 09:15 AM 06/03/13 09:15 AM
Joined: Oct 2007 Posts: 485 Raleigh, NC J j.mcconnell mopar
j.mcconnell mopar J Joined: Oct 2007 Posts: 485 Raleigh, NC	Quote: Quote: Saturday I removed the carb and squared up the transfer slots and set the idle screws at 1.25 turns out from all the way in. Initial timing was 15 degrees. The car would not idle like that. I had to screw in the idle speed screw about 4 turns to keep it alive. At that point I could still kill the engine by screwing in the idle mixture screws. I upped the initial timing to 20-22 degrees with no real improvement. I have a lean burn distributor I was going to swap in but didn't have a rotor for it. If you squared the transfer slot, turn the mixture screws out some so you can turn the idle speed down.. once you get it down then slowly turn in each mixture screw till the rpm drops then back it out 1/8 to 1/4 turn... do each one while keeping the idle speed down... I would set your timing at 18 for the base timing... you may need to curve the dist so you dont get too much Thanks, I'll give it a shot

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