Zenith Carb question

ruduger

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Greetings: After a recent rebuild (Royze), I'm experiencing a rough idle, and fouled 3 front plugs. It appears the culprit is primary jet, which dribbles fuel into venturi. I tried a different float, hoping mine was faulty, no difference. I believe the main jet size is 80. I have perused the old threads, but am not having much luck so far.
I'm sure this has occurred to more than a few of you over the years, so any advise would be much appreciated.
 

deQuincey

Quousque tandem...?
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not saying that the carbs are ok, but have you checked the whole thing,

speaking about carbs,

- table basic settings before going to the car,
- electric conexions
- air leaks
- correct synchronizing

ignition, distributor, points, condenser, gap, ...plugs, cables,

timming,...

there are some recent threads on this topic, i did one, and stevehose a better one too
 

Jean Luc

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Bonsoir il est a combien le ralenti ?

Hello how it is idle?

La pompe a essence est elle en bonne forme ?


The fuel pump is in good shape it ?
 

Stevehose

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Your throttle plate butterfly is likely open too much at idle. Back out the adjustment screw until fully closed and the screw no longer is in contact then screw it back until it just touches the linkage then perhaps another 1/4 turn. This should stop the dripping.

Also check the float valve is operating correctly
 

ruduger

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We did have the top section off the carb yesterday, and replaced the float. The float valve needle felt proper, not overly spring loaded though, but free. I had assumed that piece would have been part of the Royze rebuild kit. I wonder now whether it was shimmed to spec, which I understand is 2mm.
 

deQuincey

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We did have the top section off the carb yesterday, and replaced the float. The float valve needle felt proper, not overly spring loaded though, but free. I had assumed that piece would have been part of the Royze rebuild kit. I wonder now whether it was shimmed to spec, which I understand is 2mm.

2mm ?, NOP, use 1mm, please :razz:
 
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