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Author
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Topic: Now I need tuning help 700dp
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-07-2004 06:32 PM
 
I got idle screws set to the highest vacuum.Question, why would I have more vacuum with this carb then the old carb ? Any ways I got the idle screws set and the floats. But the motor still seems to be hunting or jumps alittle at idle. I did open the secondarys alittle so it would idle better just like the old 600 was set up, Any idea's ???Also I took it for a test drive it runs good expect when I floor it, it doesn't bog or seem rich. But it doesn't have the punch to it when I had the 600-VS. It was spinning at 20-30mph in 1st and hitting real hard in 2nd with the old 600vs. Now it just leaves ok with no spin at 20mph and doesn't seem to hit as hard in 2nd with the 700dp. If I hit at cruising speeds in 3rd it just lays down then goes ok. ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-08-2004).]
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 01:30 AM
Ok so I need alittle help, ok lots of help.  I'm running 66 front and 76 rear jets, a 28 front and 31 rear nozzle and a 4.5 PV with a vacuum reading of 13 at 900rpm. I closed the secondary's all the way I'll see if that will clean up idle alittle more. Ok so less low end power, means I need smaller jets, smaller nozzles ?? ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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BLstangin
Gearhead Posts: 856
From: St. James, MN
Registered: Apr 2002
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posted 09-08-2004 10:58 AM
Scoop, I'd step up the front jets some. I run a 68-69 in my 306, with a 75 in the rear, so I'd try to go up some in the front and see what it does.------------------
1970 coupe restored with the help of my dad. 306 with 600 holley, Weiand Stealth intake, headers, mme custom roller cam, harland sharp roller rockers, kb pistons, 10.3:1 compression ratio, pertonix ignitor 2 with matched coil, lakewood bellhousing, 4-speed toploader, and 2.79 open 8" rear. Soon to be 9" 3.50 trac-lok
1986 f-150, 5.0, factory towing package with original c-6 trans
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Glens67
Gearhead Posts: 522
From: Middleton, ID
Registered: Mar 2002
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posted 09-08-2004 01:46 PM
Skoop try a 6.5 power valve if you have 13" vac.
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Glen
67 GT 390
65 Galaxie 500 XL 4 Speed
It was not a Red Light they gave me a Slow Tree
I WAS NOT LATE the Tree was Fast
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 03:14 PM
quote:
Originally posted by Glens67:
Skoop try a 6.5 power valve if you have 13" vac.
Ok I might give that a try, but wouldn't a 4.5 kick in at a lower vacuum the a 6.5 ? Wouldn't that make it more rich at cruise speeds ?The motor idles even worst then ever now. I closed the secondarys all the way. And I have to move the idle to 1000park and 850 in drive. To get it to stay running, so I'm going to open the secondarys alittle again, reset the idle mixture screws and see what happens. I changed the nozzles to 35 front and rear, that helped ALOT still not the same at 2nd gear shifts can't get any cirp at all. But I floored from a stop  ice skating until I let out of it,then hit it again at about 15mph and still spun alittle. Still seems to missing something ?
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SCOOP
oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-08-2004).] [This message has been edited by Fastymz (edited 09-08-2004).]
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 03:20 PM
Goes down the road ok, but if I'm not into the gas or in low RPM range it seems like it's loading up ?I father inlaw said yesterday it pop just alittle out the carb on one of the start ups. Could it be a bad PV ? ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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capri man
Gearhead Posts: 8777
From: doerun, ga.
Registered: Nov 2000
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posted 09-08-2004 03:46 PM
do you have a bigger squirter that you could try in the front. ------------------
mike r
racing is real
everything else is just a game.
81 capri-302-7.33 @92mph 1/8
1.54 60 ft. http://www.angelfire.com/ny5/billswebsite/pg06.html
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 04:12 PM
Why yes I do Mike, I have a number 37 I could try.I'm trying to get it idle better too. I tried ajusting the A/F screws it helped alittle got alittle more vacuum out of it. Around 13-14 at 900 rpm. I openned the secondarys alittle which allowed me to bring the idle down alittle. But it's still running real rough and then smooth at idle. So I'm going to try a new PV should I try a 3.5 or a 6.5 ? Does any one know why a different carb would make more vacuum at idle, was the old just leaking ? ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 04:14 PM
I also noticed the rear nozzles were dripping alittle not all the time. I kept lowering the rear floats until it stopped I think.What would make just the rear nozzle drip and squirt out alittle gas now and then ? Sorry one more question, why doesn't the car die when I hold my hand over the choke tower,but if I place it over the seconadary side only it dies real fast ?
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SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-08-2004).]
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capri man
Gearhead Posts: 8777
From: doerun, ga.
Registered: Nov 2000
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posted 09-08-2004 04:42 PM
try the 37 in the front just for grins and giggles!!  dont drop the screw in the carb!!  be sure the little washer is under it. i would go with the 6.5. the drip could be the floats were to high. you know that the fuel should be just at the bottom of the sight plug, right? also make sure that the rear pump arm aint a little to tight. gotta go drink some beer, check on you a little later buddy.------------------
mike r
racing is real
everything else is just a game.
81 capri-302-7.33 @92mph 1/8
1.54 60 ft. http://www.angelfire.com/ny5/billswebsite/pg06.html
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steve'66
Gearhead Posts: 9835
From: Sonoma,CA,USA
Registered: Mar 2000
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posted 09-08-2004 04:55 PM
quote:
Originally posted by Fastymz:
I also noticed the rear nozzles were dripping alittle not all the time. I kept lowering the rear floats until it stopped I think.What would make just the rear nozzle drip and squirt out alittle gas now and then ? Sorry one more question, why doesn't the car die when I hold my hand over the choke tower,but if I place it over the seconadary side only it dies real fast ?
Because you are idling off the secondaries. There's no need to do that, close the secondaries at idle and make the primary idle circuit work properly. If you can't get it to idle right off the primaries, then it's time to open it up and spray out the passages, etc. Good luck, SteveW
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-08-2004 07:04 PM
Ok I closed off the secondarys and tried to adjust the A/F but it's still running bad at idle seems to load up? and it runs worst then with the secondarys open alittle?
I loosend the secondary pump it was real tight. It's no longer dripping from the rear nozzle.I'm going to change the PV to a 6.5 should I change the jets to while I'm at it ? ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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capri man
Gearhead Posts: 8777
From: doerun, ga.
Registered: Nov 2000
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posted 09-08-2004 08:38 PM
nope, the jets should have nothing to do with your idle.------------------
mike r
racing is real
everything else is just a game.
81 capri-302-7.33 @92mph 1/8
1.54 60 ft. http://www.angelfire.com/ny5/billswebsite/pg06.html [This message has been edited by capri man (edited 09-08-2004).]
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steve'66
Gearhead Posts: 9835
From: Sonoma,CA,USA
Registered: Mar 2000
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posted 09-08-2004 10:43 PM
Ron,I agree, take it apart and clean it again. Maybe some teflon tape is in the passages now. ? It shouldn't be this hard. I hope everyone reading this knows that this is a used carb. SteveW p.s. take a straight edge to the metering blocks and the main body to make sure it's straight.
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-09-2004 01:05 AM
This has to be one of the hardest "EASY" projects I've ever done. After I got this used carb like Steve said, I took my time cleaning it, and used all new gaskets, needle seats etc. I use carb cleaner, then used compressed air to make sure it's all clean.Tonight I changed to a 6.5PV and blew out the front meter plate and A/F screws. I restarted the car it ran good for a few second until I noticed YES ANOTHER FUEL LEAK  from the inlet fitting the nylon gasket twisted, I'm sure I over tightend it. I'm so sorry to post this much and take all your time. On a stupid carb change  After it starting leaking agian I just cleaned up my mess and walked away. ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-09-2004).]
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-09-2004 01:08 AM
quote:
Originally posted by steve'66:
Ron,? It shouldn't be this hard. I hope everyone reading this knows that this is a used carb. SteveW p.s. take a straight edge to the metering blocks and the main body to make sure it's straight.
I did the straight edge when I rebuilt it. I did check the linkage like you said. The carb was only openning about 1/2-2/3's of the way. I adjusted to open fully with the pedal to the floor, some reason my son liked that part. I did this with the car off. So I hope it's not flooded now too.
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SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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bud4660
Gearhead Posts: 542
From: Mesquite, Tx. M&M #2925
Registered: Apr 2003
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posted 09-09-2004 01:54 PM
Hey Scoop. You know you love working on Holleys!!!
"I'm running 66 front and 76 rear jets, a 28 front and 31 rear nozzle and a 4.5 PV with a vacuum reading of 13 at 900rpm."I dont like to run that big of gap between fronts and rears. If its rich on the fronts take them down. Also bring the backs down to within 2 sizes of the fronts to start with. IE 70 front, 72 rear. The power valve needs to go up to the 6.5 . When you hit the throttle the vacuum starts to drop. Thats when the PV opens. So the closer it is to your vacuum the sooner it will richen the fuel up. Thats why you dont need big jets to start with. You will have to read the plugs to get it dead on. I like big squirters and 50cc pumps. I run the linkage as tight as I can get it. If it backfires it can blow the PV. I always keep extras for that reason. Take the jets down as low as you can and work them up 2 sizes at a time. It just takes time to get it there. I think I have more Holley parts than they do....lol
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-09-2004 04:21 PM
Thanks, once I get all the leaks fixed.I start tuning it better. I hope the new 6.5 PV helps sort out the idle. As for the jets I'll leave them alone until I get it to idle good. Then I'll change the plugs and take it for a a few test drives. Having the carb openning all the way should help too. ------------------
SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics
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bud4660
Gearhead Posts: 542
From: Mesquite, Tx. M&M #2925
Registered: Apr 2003
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posted 09-09-2004 04:30 PM
quote:
Originally posted by Fastymz:
Thanks, once I get all the leaks fixed.I start tuning it better. I hope the new 6.5 PV helps sort out the idle. As for the jets I'll leave them alone until I get it to idle good. Then I'll change the plugs and take it for a a few test drives. Having the carb openning all the way should help too.
Well the only way the PV can help the idle is if its blown already and has fuel pouring out it. If the metering block gaskets are wrong it will leak fuel down in the bore and flood too. Been there done that....lol
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SteveLaRiviere
Administrator Posts: 48752
From: Saco, Maine
Registered: May 99
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posted 09-12-2004 08:17 PM
If the bowls are still leaking with the new fuel line you got, the threads must be too sloppy. Out of the dozens of Holleys I've run I've never had them leak there.------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
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Fastymz
Moderator Posts: 22791
From: Reno Nv M&M #1240
Registered: Apr 2001
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posted 09-14-2004 01:51 AM
This time it was me. I over torqued(something I do to much of ) the inlet line to the bowl and push the nylon washer out of shape. No body in town had any so I have wait for some to be sent to me.If I can't get it to idle and stop leaking this time. I might just take it in to the carb guy in town ?
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SCOOP oddly obsessed with big scoops on little Mustangs 65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc. My Pics [This message has been edited by Fastymz (edited 09-14-2004).]
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Big D
Gearhead Posts: 6843
From: WELLS, NEVADA USA
Registered: Nov 2000
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posted 09-16-2004 02:25 AM
SCOOP,,So what did you do - put the WHAMMY on me.. The last couple of time I took 6T6 out for a short spin,, I noticed it was running a little rough,, so tonight I opened the hood,, started it,, and as I was getting out to take a looksee -it started to die - I went to reach for the throttle and gas was leaking all over the place.. GRRRRRRRRRR..  The screws on the Accelerator Pump were loose.. Glad I caught it before it caused a real problem.. ------------------
Don
6T6 Fastback
331 STROKER,, WC T-5
Royal Blue Metallic w/Red-Blue Ghost Flames
http://mustangsandmore.50megs.com/MembersPics/BigD.html
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