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RichNJohn
Samba Member
Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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 Posted: Sun Apr 15, 2018 1:25 pm Post subject: 72 super idle adjustment |
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I've been trying to get the idle set correctly on my 72 Super. I adjusted the fast idle so the screw just touched the bottom step on the throttle cam then went 1/4 turn further. Then I adjusted the volume control screw by bottoming it out then backed off 2 1/2 turns, then adjusted the idle using the large bypass screw. Fine tuned the volume control by adjusting it to fastest idle point then back until the point it dropped the rpm a little.
The engine runs good and smooth. However, It idles too slow when it's cold and when it's warm it idles too fast. When I pull up to a stop light (engine warm) it idles a little too high until I tap the accelerator to bring the idle down. What am I missing?
Second question. I have a set screw to the right of the fast idle adjustment screw (see picture) that I can't find any reference for. All the Solex pictures I can find show a single fast idle adjustment screw. Does anyone know what that screw is for and how/if it should be adjusted?
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Starbucket
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Joined: April 30, 2007
Posts: 4026
Location: WA
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| Posted: Sun Apr 15, 2018 1:37 pm Post subject: Re: 72 super idle adjustment |
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| You may need to adjust the choke (3 hold down screws). Look at your fast idle cam when engine is at the point you have to tap the throttle to make it idle slower and leaving it idling fast go to the carb and "tap the throttle" with your hand and see if the cam moves to change the idle, if so adjust the choke heat element (loosen 3 screws a little) and move center until fast idle cam stays in the slow idle position. |
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mukluk
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Joined: October 18, 2012
Posts: 7028
Location: Clyde, TX
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| Posted: Sun Apr 15, 2018 1:46 pm Post subject: Re: 72 super idle adjustment |
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The extra screw is used to adjust the throttle positioner if the car had one installed, yours doesn't. You can leave it as is or remove it entirely, up to you.
Since tapping the throttle gets the idle speed to drop down at idle when warm, I'd suspect either the choke isn't opening fully, the throttle cable is too tight, or the throttle shaft is binding slightly when almost closed. The low speed when cold and high when warm points toward an idle mixture problem -- could be due to the choke needing adjustment, the volume control screw needing further tweaking, idle jet is the wrong size, carb needs to be cleaned, carb preheat isn't working...
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1960 Ragtop w/Semaphores "Inga" |
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David_nc_72std
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Joined: August 22, 2015
Posts: 841
Location: Winston-Salem, NC
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| Posted: Sun Apr 15, 2018 8:57 pm Post subject: Re: 72 super idle adjustment |
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| mukluk wrote: |
The extra screw is used to adjust the throttle positioner if the car had one installed, yours doesn't. You can leave it as is or remove it entirely, up to you.
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Your carburetor has an extra "arm" for the throttle positioner, adjacent to the throttle arm, that is used by the throttle positioner to slightly hold the throttle open on rapid deceleration. Since you are missing the throttle positioner, turn the adjusting screw in as far as it will go, that will hold the arm out of the way so it won't flop around. |
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RichNJohn
Samba Member
Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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| Posted: Mon Apr 16, 2018 5:59 am Post subject: Re: 72 super idle adjustment |
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| All good info/suggestions. Thank you |
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RichNJohn
Samba Member
Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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| Posted: Wed Apr 18, 2018 6:25 am Post subject: Re: 72 super idle adjustment |
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| I've adjusted everything and discovered that once warm, the throttle doesn't completely close when the accelerator is released. I even loosened the cable until it is so loose I can see slack in it but there is still a little slop in the throttle. I put a shorter return spring on the throttle which helps quite a bit but still not quite right. Maybe the old carb is just worn out? |
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FeelthySanchez
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Joined: February 03, 2011
Posts: 1349
Location: Now is that a real poncho, or a Sears poncho?
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| Posted: Wed Apr 18, 2018 7:20 am Post subject: Re: 72 super idle adjustment |
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Will suggest checking the torque on the 13mm carb base flange nuts.
If you do find them loose, pop the carb off to replace the gasket - just 'cuz it does appear a bit pinched. May also discover a warped carb base & manifold flange(s).
edit: Now appears that both of the rear-facing black rubber vacuum caps are rather cracked. Amazing how a cup of strong coffee can help solve life's little mysteries ......
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| modok wrote: |
| I would like if you had enough clue to communicate what you are doing. |
| Ryan Tucker wrote: |
| Enough clue..Whats that mean? |
| OldIronSpine wrote: |
I'm not sure how compression works.
Turbos don't produce torque, they produce HP. Instead of torque.
The real problem with NA engines is you don't hear the nice whine of the turbo as it spools up.
Before I commit, I'm going to do more research because I don't really know what piston rings are. |
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djack47
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Joined: October 21, 2010
Posts: 52
Location: Poteau OK
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| Posted: Wed Apr 18, 2018 10:27 pm Post subject: Re: 72 super idle adjustment |
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You did Clean the idle jet good,Right?
Jack |
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mukluk
Samba Member
Joined: October 18, 2012
Posts: 7028
Location: Clyde, TX
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| Posted: Thu Apr 19, 2018 1:27 pm Post subject: Re: 72 super idle adjustment |
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| RichNJohn wrote: |
| I've adjusted everything and discovered that once warm, the throttle doesn't completely close when the accelerator is released. I even loosened the cable until it is so loose I can see slack in it but there is still a little slop in the throttle. I put a shorter return spring on the throttle which helps quite a bit but still not quite right. Maybe the old carb is just worn out? |
It may well be the carb is worn out, allowing the throttle shaft to move a bit and bind in its bore. You can grab the throttle shaft on either side of the carb body and see if there is any axial play indicating wear; if yes but not very pronounced, try some oil at each pivot point to see if that clears up the sticking. Another thing to check is to see if the throttle plate has come loose (it's held in place in the throttle shaft by two screws), or if it is no longer centered in the carb bore when closed -- this is best done with the carb removed from the manifold. One other thing would be to check for binding or a bent linkage at the accelerator pump.
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1960 Ragtop w/Semaphores "Inga" |
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Starbucket
Samba Member
Joined: April 30, 2007
Posts: 4026
Location: WA
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| Posted: Thu Apr 19, 2018 4:12 pm Post subject: Re: 72 super idle adjustment |
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| Try spraying throttle body cleaner down the carb bore and at the pivot points to clear out any gunk causing it to stick. Look at your gas peddle and make sure crap isn't causing the peddle not to return all the way |
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RichNJohn
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Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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| Posted: Fri Jul 06, 2018 9:51 am Post subject: Re: 72 super idle adjustment |
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| Thanks all, still fiddling with it. Finally getting around to changing out the cracked vacuum caps. Reference the green vacuum hose in the picture, it goes to the temperature control valve for the air cleaner. Is that the correct port to use? Does it matter? |
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vamram 
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Joined: March 08, 2012
Posts: 7304
Location: NOVA
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| Posted: Fri Jul 06, 2018 9:59 am Post subject: Re: 72 super idle adjustment |
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The port the the green hose is on should go to the retard nipple on a DVDA distributor vacuum can, not to the air cleaner. You should remove the hose and plug the port if you don't have a DVDA and then check your timing and carb adjustment again.
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Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!
'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!! |
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RichNJohn
Samba Member
Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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| Posted: Fri Jul 06, 2018 12:32 pm Post subject: Re: 72 super idle adjustment |
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| Thank you. Unfortunately I have an 009 (for now) so need to plug that port. Where should the hose going to the air cleaner attach? |
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vamram
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Joined: March 08, 2012
Posts: 7304
Location: NOVA
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| Posted: Fri Jul 06, 2018 2:10 pm Post subject: Re: 72 super idle adjustment |
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The one to the air cleaner attaches to a nipple on the neck of the intake manifold, just below the left of the carburator. Like in this pic.
Hard to tell from your picture, but it looks like you have a single port manifold w/out the fitting for the line.
_________________
Eventually, "we are what we pretend to be.’”
Give peace a chance - Stop Russian-Soviet Aggression!!
'74 Super 9/16 - present, in refurb process.
'73 Super - 6/18 - Present - Daily Driver!
'75 Super Le Grande...waiting it's turn in line behind '74.
Click to view image
Save the Supers!! |
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RichNJohn
Samba Member
Joined: April 07, 2017
Posts: 91
Location: Palm Springs, CA
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| Posted: Fri Jul 06, 2018 5:31 pm Post subject: Re: 72 super idle adjustment |
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| Ok, now this is making more sense to me. I have a 72 which should have a 1600DP engine but someone put a 1500 SP engine in it. Explains why I have no port for the air cleaner. I guess I'll try capping the port and just won't have the pre-heat on the air cleaner for now. Thank you! |
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