I was trying to balance my 40 idf weber carbs at idle on Saturday. They are equal left to right. 1 and 4 are almost equally the same. Just under 4 on my air flow meter while 2 and 3 are just a fraction higher. There isn't much in it but then I had the idea of opening the air bypass screws on 1 and 4 to rise the air flow a little. However, I cracked out the nut but it didn't change the flow. Now looking at the diagram again I think I need to loosen the nuts then screw out the bypas screw (which I didn't do) and retighten the nut? Works a bit like when adjust the valves?
Weber air bypass screws!
- Neil Bardsley
- 356 Fan
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- Jim Karaba
- 356 Fan
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Re: Weber air bypass screws!
Yes the nut is just a locking nut to maintain the bypass adjustment
- Neil Bardsley
- 356 Fan
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- Location: London
Re: Weber air bypass screws!
thank youJim Karaba wrote:Yes the nut is just a locking nut to maintain the bypass adjustment
- John Brooks
- 356 Fan
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Re: Weber air bypass screws!
Out = up. In = down on the unisync
John Brooks
62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965
62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965
- Neil Bardsley
- 356 Fan
- Posts: 1100
- Joined: Tue Mar 20, 2012 10:21 am
- Location: London
Re: Weber air bypass screws!
Thanks I did this on my 912, which also has 40 webers, and got the front back cylinders in sync. Once they were you could hear the engine rev smoother and faster. I checked the valves before and I think they are good. Could incorrectly set valves impact the flow?
- Jim Karaba
- 356 Fan
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