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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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 Posted: Mon Jul 24, 2017 5:56 pm Post subject: 71 super popping at idle |
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Hi all I'm slowly but surely getting my 71 super road worthy one gremlin at a time. Since the day I bought it there has been this popping and what sounds like it's missing at idle, anywhere else in the upper rpm range it seems to be fine.. today I adjusted the valves at .006, static timed it and put in new plugs the idle sounds great purrs way better but the popping hasn't gone away at all... a buddy of mine swears it's just the plug wires, I have just posted a YouTube video so you can hear any suggestions would be great.. thank you
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miller0358
Samba Member
Joined: November 07, 2007
Posts: 1200
Location: northford,ct
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| Posted: Mon Jul 24, 2017 7:40 pm Post subject: Re: 71 super popping at idle |
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| Is it popping thru the carb or exaust?? |
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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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| Posted: Mon Jul 24, 2017 7:48 pm Post subject: Re: 71 super popping at idle |
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| miller0358 wrote: |
| Is it popping thru the carb or exaust?? |
Thru the exhaust |
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miller0358
Samba Member
Joined: November 07, 2007
Posts: 1200
Location: northford,ct
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| Posted: Tue Jul 25, 2017 2:16 pm Post subject: Re: 71 super popping at idle |
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| Start with taking a compression check. Sounds like you could have a bad valve. Jeff |
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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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| Posted: Tue Jul 25, 2017 2:33 pm Post subject: Re: 71 super popping at idle |
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| You think maybe it could also be that I have to recheck my points gapping? |
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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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| Posted: Wed Jul 26, 2017 10:43 am Post subject: Re: 71 super popping at idle |
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| Well I've been digging into it a little bit more this morning and I recall when I was trying to reset the carburetor idle and idle speed and what not I remember that it wouldn't really adjust as to where it would make a difference like starts tumbling or speed up so now I'm thinking to pull out the needles idle speed and bypass to see if the O-rings are intact I'm thinking that this could be it |
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Tangerine
Samba Member
Joined: May 09, 2016
Posts: 41
Location: North Central Arkansas
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| Posted: Thu Jul 27, 2017 3:15 pm Post subject: Re: 71 super popping at idle |
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I don't mean to hi-jack your thread, but I have a similar problem. On a 71 Super, what would cause it to backfire through the exhaust when you let off the gas?
Thanks.
LarryT
_________________
68 Variant FI
71 SB Sedan
73 SB Cabriolet |
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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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| Posted: Thu Jul 27, 2017 5:16 pm Post subject: Re: 71 super popping at idle |
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| Tangerine wrote: |
I don't mean to hi-jack your thread, but I have a similar problem. On a 71 Super, what would cause it to backfire through the exhaust when you let off the gas?
Thanks.
LarryT |
Now that issue is a little different 9 times out of 10 ill put my money on an exhaust leak especially on decal only.. check your joints and couplers look for soot start her up feel around with your hand as well |
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FeelthySanchez
Samba Member
Joined: February 03, 2011
Posts: 1349
Location: Now is that a real poncho, or a Sears poncho?
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| Posted: Thu Jul 27, 2017 8:06 pm Post subject: Re: 71 super popping at idle |
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Was the carb up-jetted sometime after that gauze air cleaner was installed?
Worst case here: somebody just threw-on a kool-lookin' aftermarket air filter, ignoring the changes it made to intake air flow, signals & restrictions.
Here's some info:
Assuming no vacuum leaks or major/oddball engine wear 'n tear condition(s), popping thru the exhaust @ idle is a classic symptom of a too-lean carburetor adjustment.
Does she pop when stone cold, ala when the choke is closed? If so, could be other problems.
If not, light the fires.
Twist open (CCW) the fuel/air mixture screw by an increment of 1/2 turn & listen.
If she's still popping, go 'nuther 1/2 turn out. Continue as necessary.
When it eventually quits popping, twist the screw CW (back IN) by 1/4 turn & listen again.
If she then quits popping at some point here, you've found the sweet spot & may now congratulate yourself. Bust-open a kold brew 
_________________
| 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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Kobra101
Samba Member
Joined: April 10, 2017
Posts: 64
Location: Davie fl.
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| Posted: Fri Jul 28, 2017 3:35 pm Post subject: Re: 71 super popping at idle |
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Excellent thank you very much for that reply!.. it actually beginds to pop just after it warms up and comes fully off the choke.. I'm going to try what you said because what ive been doing is bringing it out the standard 2 1/2 turns and opening it from there after going 1 to turns more it still didn't stop so I stopped opening it, I'm going to try and go a little further and see what it does its funny because as im adjusting theres almost no change I would have that going nearly 2 revolutions out would give me a little something
| FeelthySanchez wrote: |
Was the carb up-jetted sometime after that gauze air cleaner was installed?
Worst case here: somebody just threw-on a kool-lookin' aftermarket air filter, ignoring the changes it made to intake air flow, signals & restrictions.
Here's some info:
Assuming no vacuum leaks or major/oddball engine wear 'n tear condition(s), popping thru the exhaust @ idle is a classic symptom of a too-lean carburetor adjustment.
Does she pop when stone cold, ala when the choke is closed? If so, could be other problems.
If not, light the fires.
Twist open (CCW) the fuel/air mixture screw by an increment of 1/2 turn & listen.
If she's still popping, go 'nuther 1/2 turn out. Continue as necessary.
When it eventually quits popping, twist the screw CW (back IN) by 1/4 turn & listen again.
If she then quits popping at some point here, you've found the sweet spot & may now congratulate yourself. Bust-open a kold brew |
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FeelthySanchez
Samba Member
Joined: February 03, 2011
Posts: 1349
Location: Now is that a real poncho, or a Sears poncho?
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| Posted: Mon Sep 04, 2017 7:17 pm Post subject: Re: 71 super popping at idle |
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Alright, kool.
Below symptom sounds like it's under-jetted, needs overhaul or else a stray vacuum leak.
Could you advise re what the carb's pedigree/condition is: German, Brazzy, chi-knees? Recently rebuilt?
[quote="Kobra101"] ..... it actually begins to pop just after it warms up and comes fully off the choke..
_________________
| 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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