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TR6 tuning webbers
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The problem is that too-high fuel pressure is possible. If the fuel pressure is above about 3.5 PSI, fuel can be pushed past the float valve and cause flooding. If you are using a mechanical pump, there is no easy way to adjust the fuel pressure, so I think that's why they recommend a regulator. Three problems with that, though: first, many regulators are trash; second, many won't work well with a mechanical pump, and third, the regulator may not work well with a small difference between the input and output pressures.
I use an electric pump that puts out about 6-7 PSI and a Holley regulator to bring it down to about 2 PSI, which is plenty. I also have a pressure gauge permanently connected to the regulator. That's not necessary, of course, but since I've had fuel-pressure problems in the past, I like being able to check the pressure at a glance.
If I had to reduce the fuel pressure with a mechanical pump, I think I'd be tempted to try trimming the spring. I've never tried that, though, so the suggestion might be nonsense.
I use an electric pump that puts out about 6-7 PSI and a Holley regulator to bring it down to about 2 PSI, which is plenty. I also have a pressure gauge permanently connected to the regulator. That's not necessary, of course, but since I've had fuel-pressure problems in the past, I like being able to check the pressure at a glance.
If I had to reduce the fuel pressure with a mechanical pump, I think I'd be tempted to try trimming the spring. I've never tried that, though, so the suggestion might be nonsense.
Tybalt
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You might want to take a look at this thread:
www.britishcarforum.com
It goes back to 2011 but is brought back to life in post #5 from November 2021. It follows a refreshing of triple 40DCOEs on a TVR 2500M over several months. Some good information in that thread on the DCOE.
TVR 2500M Triple Weber 40 DCOEs
I have a question for the TVR/Triumph guys out there. I own a 1974 TVR 2500m and it has three weber 40 DCOE carburetors on it. These carbs look great, but the problem is that there is a stumble in the acceleration of the car. I have to take off very slow until the RPMs are higher in range. It is...
www.britishcarforum.com
It goes back to 2011 but is brought back to life in post #5 from November 2021. It follows a refreshing of triple 40DCOEs on a TVR 2500M over several months. Some good information in that thread on the DCOE.