Running on 7 cylinders

[Rick Parker]

I finished the Weber install (pic in the gallery) but I find myself with a 7 cylinder engine. I have it narrowed down to either cylinder 5 or 6. I was a little short of time today but with the engine at a fast idle of about 1100 RPM there is a definate miss in the LH sidepipe. Mixture screws are open 3/4 of a turn and the airflow is quite close through all carb bodies.
Turning the mixture screws on that carb doesn't seem to have any significant affect????
Plugs are fresh


Ideas?????????????

[priobe]

Rick,

Here are a few items to check. I know I am no expert with the webers at least you can try a few things.

1) Make sure the throttle for that cylinder is seat correctly. Sometime these throttle plates are slightly opened which will not create enough vacuum to draw the fuel.

2) Make sure your carbs are properly synced. You mention that they are quite close with syncronization but they should be close to exact.

3) Pull the jets and make sure you are getting fuel in the bowl where the jets sit.

Note: I am assuming you have already checked that you are receiving spark.

Are the plugs wet with fuel ?

[Jac Mac]

Rick,

Double check your firing order-crossed leads?
Use your timing light ( inductive pickup ) on each lead to ensure you have spark at all eight.
Partially cover each venturi one at a time with your hand and listen for the engine note to 'pick up'- the stronger signal from partial choke will draw extra fuel in.
Since each carb bowl serves 2 cyls then it shouldnt be fuel level but could be a blocked jet/passage etc.
Basics first- Comp test and /or Leakdown.

Jac Mac

[Eljaro]

Rick,

you mean cylinder 5 or 6?
Check the jets. You may have dirt in the main or idle jet.
If you didn't blow air through all the webers galleries during assembly you may find some debris has got to the jets. Nothing else can cause that if your ignition is ok.
New carbs aren't 100% clean out of the box!