carb air flow way off
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- sevenmilebridge
- Roadster Fanatic
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- Joined: Fri Dec 23, 2016 10:53 am
carb air flow way off
Front carb on my 1600 drawing lots of air rear carb hardly any air flow. Possible weak spring on piston?? very frustrating any thoughts
65 Mustang work in progress 69 2000 Dialed in 69 2000 work in progress 70 1600 work in progress
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- Roadster Nut-Site Supporter
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Re: carb air flow way off
Have you checked valve lash yet?
located in Chester NH
1967 1600 in restoration
2013 Arctic Cat F-1100 turbo
Ford F-350 6.0
Ford 9000 puller, Ford 960 puller, Ford 901show, Ford 971 worker, Oliver 70 waiting its turn
1967 1600 in restoration
2013 Arctic Cat F-1100 turbo
Ford F-350 6.0
Ford 9000 puller, Ford 960 puller, Ford 901show, Ford 971 worker, Oliver 70 waiting its turn
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- Roadster Fanatic-Site Supporter
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- Joined: Sat Nov 21, 2009 11:37 pm
- Location: Vancouver, Washington
- Model: 1500/1600
- Year: High Windshield-68-70
Re: carb air flow way off
Valve lash
Choke hanging up
Vacuum leak
Are you not able to balance air flow? Can you describe your process?
.
Dan
Choke hanging up
Vacuum leak
Are you not able to balance air flow? Can you describe your process?
.
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
- sevenmilebridge
- Roadster Fanatic
- Posts: 155
- Joined: Fri Dec 23, 2016 10:53 am
Re: carb air flow way off
Checked valves they are in adjustment. There is no vacuum leak. The difference is significant I haven"t run into this problem before. I"m about to tear out what little hair i have left.
65 Mustang work in progress 69 2000 Dialed in 69 2000 work in progress 70 1600 work in progress
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- 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: carb air flow way off
I had a similar issue with our 1600. I found the choke cable was holding the front carb nozzle up a bit.
I loosened both choke cable clamp screws and used the "magic number" to set the nozzle heights. Once that was done, it was pretty close (within a quarter turn".
I like my snail for measuring flow, it's easier for me to read then a floating ball.
Sounds like you've been battling this for a while. You may be best off to start from a base line (that's the advantage of setting the nozzle in the body at a measured height).
Dan
I loosened both choke cable clamp screws and used the "magic number" to set the nozzle heights. Once that was done, it was pretty close (within a quarter turn".
I like my snail for measuring flow, it's easier for me to read then a floating ball.
Sounds like you've been battling this for a while. You may be best off to start from a base line (that's the advantage of setting the nozzle in the body at a measured height).
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
- Gregs672000
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Re: carb air flow way off
It has to be a linkage problem. I suggest examining how the linkage works to adjust the carbs. I don't have fully stock linkage and found that the way I had it set up would not allow for the balancing linkage to work right (Dellorto carbs, so somewhat different set up), but it took really looking at what was happening to understand what needed to change.
I would disconnect the linkage between the two carbs and get each carb flowing the same air, then see what happens when you reconnect them via the balancing linkage. As I recall, both carbs have a screw that will directly move the throttle plate individually, so start there by getting them to flow the same, then address the balancing linkage issue. Think about it: One carb is not being allowed to flow the same amount of air, and the flow of air is determined by the carbs throttle plate only. Something is changing the position of that plate.
I would disconnect the linkage between the two carbs and get each carb flowing the same air, then see what happens when you reconnect them via the balancing linkage. As I recall, both carbs have a screw that will directly move the throttle plate individually, so start there by getting them to flow the same, then address the balancing linkage issue. Think about it: One carb is not being allowed to flow the same amount of air, and the flow of air is determined by the carbs throttle plate only. Something is changing the position of that plate.
Greg Burrows
'67 2000 #588
Tacoma, WA
'67 2000 #588
Tacoma, WA
- SLOroadster
- Roadsteraholic
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Re: carb air flow way off
Your carbs are out of balance. Balance the carbs with a unisyn and see how that works.
Will
Will
Sorry, I find modern engine swaps revolting. Keep your G, R, or U series in your Roadster!
- jrusso07
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Re: carb air flow way off
As Keith at Roadster ranch instructs- take all adjustments to neutral- that is, loosen the chokes, loosen the throttle, loosen the balance screw turn the mixtures all the way in CCW. Then find initial setting s from the manual and start from there.
Else you aren’t pulling any vacuum on that carb due to a major problem - cracked isolator, bad cam...?1
Else you aren’t pulling any vacuum on that carb due to a major problem - cracked isolator, bad cam...?1
Joe
1969 SRL311 - Solex
1970 SPL311 - U20 mod
1970 SRL311
1969 SRL311 - Solex
1970 SPL311 - U20 mod
1970 SRL311