Need Help. Webers running rich

[Bill D]

Bought the manifold from one company and the Webers from Weber carbs direct

[vntgspd]

In addition to the requests above...

1. Is it running rich at idle and cruising under 2500rpm?
2. Is it rich under heavy throttle and over 3000rpm?
3. All the above

[HighPlainsDrifter]

Hi,
You need a camshaft that has less duration on the intake side otherwise air velocity will be non existent and can even have reversion into intake. You need a weber friendly cam before you band aid the engine.
Perry

[1795]

Originally Posted by Bill D

Bought the manifold from one company and the Webers from Weber carbs direct

Bill,

Check your paperwork that came with the carbs, there should be something there saying what the setup is. If not, contact Weber Carbs Direct and they should be able to tell you. Then post that information here and we can begin the process. Where did you get your cam from and what are the specs on it?

By the way, your fuel pressure should be around 3-3.5 psi. Some people go up to 4, but that is pushing it, especially on a street engine.

There are enough people here with knowledge, we'll get this figured out.

Jim

[1795]

Bill,

How long ago did you purchase the carbs and from what source directly? I tried to go to their website online to see if I could find some information for you with no luck. If you do not have any information from them, you can remove the main jets and idle jets and their holders by unscrewing the screen on the top of one carb and then using a screw driver to remove them. The jets and holders should have numbers on them, telling you what size they are. You can measure the choke tube inside the carb and that number should be in mm. 48 IDA's are the base size and would be fine on a 427 race engine, but are way too big for a 289/302. While my 289 race engine has 48 IDA's on it, the chokes are actually 42 mm. Some street setups may use 38 mm, 40 mm or 42 mm chokes.

Jim

[1795]

Bill,

Heer is an example of my initial setup. I am not saying that you should have this setup, this is just to provide you with an idea of some of the items and numbers that people are asking about. You may end up with similar parts to this list, but i would not suggest replicating this as it was setup for racing.

Webers are easy to take apart and configure. If you do end up needing different jets, holders, chokes, etc. Pierce Manifold is a good source, and they are in CA. When you take the screen off there will be two sets of jets there, two for each barrel. The large screw head is for the primary jet and the small one is for the idle jet.

Jim

Jim