SU Carbs - I Can't Win
Moderators: notoptoy, S Allen, Solex68
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
SU Carbs - I Can't Win
I put the new Z Therapy SU carbs on my stroker. Carbs are not my thing and I can't get them right.
I started with 15w fork oil in them. Adjusted them to 2.5 turns out. Under wide open throttle they have a flat spot in the mid-range. It's actually worse than the old carbs had. Haven't adjusted the advance on the blue tooth distributor at all.
So I changed out the oil to atf as recommended and then turned to 1.5 turns like the old carb. Seemed lean so I went to two turns. Still really flat and I continue to get the big pop out the exhaust at shut off which says rich.
I need someone who knows what to do with these things. It shouldn't be that hard I would think. Used the Unisyn on them.
But it does idle smooth now.
I started with 15w fork oil in them. Adjusted them to 2.5 turns out. Under wide open throttle they have a flat spot in the mid-range. It's actually worse than the old carbs had. Haven't adjusted the advance on the blue tooth distributor at all.
So I changed out the oil to atf as recommended and then turned to 1.5 turns like the old carb. Seemed lean so I went to two turns. Still really flat and I continue to get the big pop out the exhaust at shut off which says rich.
I need someone who knows what to do with these things. It shouldn't be that hard I would think. Used the Unisyn on them.
But it does idle smooth now.
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- spl310
- Roadster Guru
- Posts: 13234
- Joined: Sun Dec 29, 2002 10:38 pm
- Location: In front of this keyboard... in Jacksonville, Florida!
Re: SU Carbs - I Can't Win
I would love to help you, but the commute would kill me. That being said, the instructions in the shop manual are actually pretty good if you follow them exactly.
"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!
More...
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...
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
Which shop manual? I looked at Keith's and the Z therapy DVD but I'm missing something.
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- nismou20
- Roadsteraholic
- Posts: 1500
- Joined: Thu Jul 07, 2005 2:16 pm
- Location: Pasadena, Ca
Re: SU Carbs - I Can't Win
Think Keith mentions in Wiki Tech that 1600 needles tend to run rich at idle lean on top. Recommends ADQ needles for the R's. I think he has some.
2004 Chevy Tracker
2010 RAV4
1969 Datsun Roadster
2005 Lotus Elise
1995 Toyota Tercel (Poormans Corolla)
2001 Fleetwood Jamboree RV
2010 RAV4
1969 Datsun Roadster
2005 Lotus Elise
1995 Toyota Tercel (Poormans Corolla)
2001 Fleetwood Jamboree RV
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
Okay, I think I need to get hold of him. Thanks.
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
I looked at the link on here to his web site but no contact info. Not sure what name he is on here.
Never mind, I found him.
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- spl310
- Roadster Guru
- Posts: 13234
- Joined: Sun Dec 29, 2002 10:38 pm
- Location: In front of this keyboard... in Jacksonville, Florida!
Re: SU Carbs - I Can't Win
The factory shop manual - available on Wiki:
http://www.311s.org/PDFs/SPL311ServiceManualSML.pdf
"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!
More...
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...
- 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: SU Carbs - I Can't Win
See the Wiki for the "magic number" method for nozzles adjustment. Much more precise, and you can adjust from there if necessary.
Linda
Linda
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.
-
- Roadster Fanatic-Site Supporter
- Posts: 1790
- Joined: Sat Nov 21, 2009 11:37 pm
- Location: Vancouver, Washington
- Model: 1500/1600
- Year: High Windshield-68-70
Re: SU Carbs - I Can't Win
You'll find the magic number method in http://www.311s.org/pmwiki-311/pmwiki.p ... ion.SuTech
Has worked great for me.
Dan
Has worked great for me.
Dan
SPL311 aka Skooter. Sold. Now wasting away in the SF area.
1990 Nissan 300zx. Sold this one too.
2018 VW Tiguan
1990 Nissan 300zx. Sold this one too.
2018 VW Tiguan
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
I copied and pasted this in to a document and highlighted it. Thanks.greydog wrote: ↑Thu Sep 20, 2018 10:28 am You'll find the magic number method in http://www.311s.org/pmwiki-311/pmwiki.p ... ion.SuTech
Has worked great for me.
Dan
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- 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: SU Carbs - I Can't Win
If you use this method, measure each nozzle first to see how far off you are. I was way off...
Linda
Linda
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
We'll see. I would think a freshly built set of carbs would be right on but you never know. Z carbs are their first and foremost so maybe they just get them in the neighborhood. But they are pretty!
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- 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: SU Carbs - I Can't Win
They were right on til you turned the adjustment
Linda
I'd look for vacumm leaks at the spacers too etc
Linda
I'd look for vacumm leaks at the spacers too etc
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.
- Curtis
- Site Supporter
- Posts: 4143
- Joined: Fri Jan 01, 2010 2:49 pm
- Location: Des Moines, WA
- Model: 1500/1600
- Year: Low Windshield-64-67.5
Re: SU Carbs - I Can't Win
All fresh gaskets.
66 stroker, almost done.
67 basket case, paint coming soon.
67 basket case, paint coming soon.
- 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: SU Carbs - I Can't Win
I think that the nozzle adjustments can not be exactly determined by Z Therapy since engines are different. Therefor some tuning would be necessary. Then it is easy to mess up the balance using the " x number of turns out" method.
But new gaskets and firm tightness is one less thing to worry about
Seems a lot easier than electrical, which you are a whiz at!
Also I know that U20 carbs are different than R16 carbs, and since you have a stroker, which is closer to a U20, perhaps you need the U20 carb? I do not know the answer ..
Linda
But new gaskets and firm tightness is one less thing to worry about
Seems a lot easier than electrical, which you are a whiz at!
Also I know that U20 carbs are different than R16 carbs, and since you have a stroker, which is closer to a U20, perhaps you need the U20 carb? I do not know the answer ..
Linda
Sadly-Linda has passed away 2022. She was the 311's den mother and drove the first Rare-Parts ball joint project. RIP.