Carb mixture adjustment
Moderators: notoptoy, S Allen, Solex68
- BBF Roadster
- Roadster Fanatic
- Posts: 222
- Joined: Thu Oct 20, 2011 8:30 pm
- Location: Houston TX
Carb mixture adjustment
I'm trying to set the metering nozzles.
Mine are all out of wack.
If they are turned all the way in to lean,
How many turns out toward rich should they be roughly.
I hope someone can help so I can finally get it running.
Thanks
Mine are all out of wack.
If they are turned all the way in to lean,
How many turns out toward rich should they be roughly.
I hope someone can help so I can finally get it running.
Thanks
67.5 1600, U20 Swap
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
-
- Roadster Fanatic
- Posts: 361
- Joined: Sat Dec 06, 2008 12:25 am
Re: Carb mixture adjustment
Are you saying it doesn't run at all right now no matter where you set the jets? Every engine will be different but you might try a base line setting of 1 1/2 to 2 turns out from full lean. Just make sure EVERYTHING else associated with the engine's tuning is set-up and adjusted properly before going hog-wild turning jet screws.
- jrusso07
- Roadsteraholic
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- Location: Penn Yan, NY
- Model: 2000
- Year: High Windshield-68-70
Re: Carb mixture adjustment
1.5 to 2.5 toward rich is a good start. I tend to go rich as you adjust this out as you set up the system.
You should review this http://www.311s.org/su-setup/su-setup.html" onclick="window.open(this.href);return false;
You should review this http://www.311s.org/su-setup/su-setup.html" onclick="window.open(this.href);return false;
Joe
1969 SRL311 - Solex
1970 SPL311 - U20 mod
1970 SRL311
1969 SRL311 - Solex
1970 SPL311 - U20 mod
1970 SRL311
- BBF Roadster
- Roadster Fanatic
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- Location: Houston TX
Re: Carb mixture adjustment
The engine runs, but has no throttle response, just drones with no power.
I replaced the head and had it rebuilt, so also need to check valve lash.
Thanks for the ball park setting.
I replaced the head and had it rebuilt, so also need to check valve lash.
Thanks for the ball park setting.
67.5 1600, U20 Swap
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
- GeoffM
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Re: Carb mixture adjustment
If you have a micrometer, adjust the nozzles to a depth of .092" to start.
You should read this excellent write-up:
http://www.311s.org/pmwiki-311/pmwiki.p ... sNewSuTech" onclick="window.open(this.href);return false;
You should read this excellent write-up:
http://www.311s.org/pmwiki-311/pmwiki.p ... sNewSuTech" onclick="window.open(this.href);return false;
Geoff
1969 SPL-311
1969 SPL-311
- BBF Roadster
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Re: Carb mixture adjustment
I set the metering nozzles to two turns.
After a hard start again, I noticed a bad spark plug sparking around the ceramic.
Bought a new plug and it idles smoothly now. Yeah
Now when trying to rev the engine, it backfires through the carbs.
Also the distributor is set to full advance, but seems like it needs more advance.
Im very happy that it is closer to driving.
Thanks for any help guys.
After a hard start again, I noticed a bad spark plug sparking around the ceramic.
Bought a new plug and it idles smoothly now. Yeah
Now when trying to rev the engine, it backfires through the carbs.
Also the distributor is set to full advance, but seems like it needs more advance.
Im very happy that it is closer to driving.
Thanks for any help guys.
67.5 1600, U20 Swap
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
- Gregs672000
- Roadster Fanatic-Site Supporter
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- Location: Tacoma, WA
Re: Carb mixture adjustment
Dizzy may be a tooth off. There is a small degree of additional adjustment available by loosening the 8mm bolt that locks down the metal pointer on the dizzy. What is the initial timing set at? What curve? Also, check your firing order 1,3,4,2 counter clockwise. If you are not able to set the timing to where it should be you will have to remove the dizzy and set it correctly... let us know and we will walk you through it.
R or U motor?
R or U motor?
Greg Burrows
'67 2000 #588
Tacoma, WA
'67 2000 #588
Tacoma, WA
- BBF Roadster
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Re: Carb mixture adjustment
Thanks to everyone.
I pulled the distributor and started over.
The oil drive was 180 off,then I cleaned and greased the distriburator so the vacuum advance would work.
Now it idles smooth and revs like a beast.
Now I will hook up the new clutch cylinders and get my first attempt to drive this car.
But I better not go far since I have no brakes yet. Lol
I pulled the distributor and started over.
The oil drive was 180 off,then I cleaned and greased the distriburator so the vacuum advance would work.
Now it idles smooth and revs like a beast.
Now I will hook up the new clutch cylinders and get my first attempt to drive this car.
But I better not go far since I have no brakes yet. Lol
67.5 1600, U20 Swap
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
69 GTO
70 Barracuda
70 Roadrunner
70 Mustang FB
71 GMC Sprint SP 454
72 El Camino SS 454
-
- Roadsteraholic
- Posts: 2754
- Joined: Thu Aug 05, 2010 11:06 am
- Location: Houston TX
Re: Carb mixture adjustment
That's what the e-brake is for on these cars (in south TX where it's flat).
Just make sure the e-brake is CONNECTED first though
Good to hear you got her running smoothly.
James
Just make sure the e-brake is CONNECTED first though
Good to hear you got her running smoothly.
James
SRL311-00275
'96 Porsche 993 C4
2001 Excursion 7.3l
'96 Porsche 993 C4
2001 Excursion 7.3l
- v8_ranch
- Roadster Fanatic
- Posts: 109
- Joined: Sat Oct 10, 2020 11:13 pm
- Location: Jackson, TN
- Model: 2000
- Year: High Windshield-68-70
Re: Carb mixture adjustment
I know this is an old thread, but just wanted to say thanks! It affirms everything I have sort of stumbled into today working on my 68, after getting confused by reading a lot of other information about what to expect from the SU carbs.
Shane
1968 SRL Project
1968 SRL Project
- Linda
- Fraternal Den Mother-RIP
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- Location: Los Angeles
- Model: 1500/1600
- Year: High Windshield-68-70
Re: Carb mixture adjustment
I think the .092 nozzle depth mentioned is confused with the .092 nozzle opening size for the 1600, as stated in the Tech Wiki article.
http://www.311s.org/pmwiki-311/pmwiki.p ... sNewSuTech
Linda
You are reading, which is GOOD
http://www.311s.org/pmwiki-311/pmwiki.p ... sNewSuTech
Linda
You are reading, which is GOOD
Last edited by Linda on Tue Nov 03, 2020 8:33 pm, edited 1 time in total.
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.
- v8_ranch
- Roadster Fanatic
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- Joined: Sat Oct 10, 2020 11:13 pm
- Location: Jackson, TN
- Model: 2000
- Year: High Windshield-68-70
Re: Carb mixture adjustment
Yeah, I saw that as well, but was mostly looking at the baseline settings for mixture adjustment. Still trying to find a depth for the 2000, but I guess it probably doesn't matter if you know the approximate number of turns...
Shane
1968 SRL Project
1968 SRL Project
- Linda
- Fraternal Den Mother-RIP
- Posts: 7807
- Joined: Sat Nov 05, 2005 11:37 pm
- Location: Los Angeles
- Model: 1500/1600
- Year: High Windshield-68-70
Re: Carb mixture adjustment
Problem for me with “approx number of turns†is it is too “approximate†and therefor hard to “match†the carbs as well. I always thought “2 turns†etc was easy to duplicate, but measuring showed something else.
I suppose you could do “ 2 turns out†or whatever, then pull the domes and try to match per a measurement, then reassemble and run. Keep doing that till correct. Tedious, but once set the carbs should be good. Matching is important per ZTherapy instructions so I figure it is worth pursuing, but others might not care...
Linda
Nozzle size for 2000 is.100 per TW
I suppose you could do “ 2 turns out†or whatever, then pull the domes and try to match per a measurement, then reassemble and run. Keep doing that till correct. Tedious, but once set the carbs should be good. Matching is important per ZTherapy instructions so I figure it is worth pursuing, but others might not care...
Linda
Nozzle size for 2000 is.100 per TW
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.
- v8_ranch
- Roadster Fanatic
- Posts: 109
- Joined: Sat Oct 10, 2020 11:13 pm
- Location: Jackson, TN
- Model: 2000
- Year: High Windshield-68-70
Re: Carb mixture adjustment
Good thinking...Linda wrote: ↑Tue Nov 03, 2020 8:36 pm Problem for me with “approx number of turns†is it is too “approximate†and therefor hard to “match†the carbs as well. I always thought “2 turns†etc was easy to duplicate, but measuring showed something else.
I suppose you could do “ 2 turns out†or whatever, then pull the domes and try to match per a measurement, then reassemble and run. Keep doing that till correct. Tedious, but once set the carbs should be good. Matching is important per ZTherapy instructions so I figure it is worth pursuing, but others might not care...
Linda
Nozzle size for 2000 is.100 per TW
Shane
1968 SRL Project
1968 SRL Project
- spl310
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Re: Carb mixture adjustment
If you want absolute accuracy, get a Gunson Colortune.
"Wow, a Roadster!" Stuart Little
1967.5 2000
1967.5 2000
1964 1500
1964 1500
1967.5 1600
1968 chassis
2006 Acura MDX
2013 Volkswagen Jetta TDI wagon
1995 F350 Powerstroke!
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1967.5 2000
1967.5 2000
1964 1500
1964 1500
1967.5 1600
1968 chassis
2006 Acura MDX
2013 Volkswagen Jetta TDI wagon
1995 F350 Powerstroke!
More...