Zenith Carb Rebuild

170bdlx

170bdlx

Junior Member
I am rebuilding three carbs and need some advice about the main and cap jets. I see that both jets should be at the same level in the lower body at the narrowest point in the venturi. All three of mine are not when one washer is added tom each. The main jet is higher on all three carbs. It takes three washers on the main jet to make it level with the cap jet, then they are level and seem to be at the correct point on the venturi. Is this normal?
 
Cap jet
When installed with a gasket washer, it's tip should be level with (to 1/16" below) the lower casting shelf that the Venturi sits on.

Main jet
When installed with a washer, its tip should be level with the Lower Casting shelf that the Venturi sits on. So, when you remove a Main Jet, make sure you also dig out the old gasket. If you end up with multiple gaskets installed, it will cause poor performance and leaks, because the Jet tip isn't precisely where it should be in the Venturi.
Ck out this site very informative
http://www.modela.org/components.html
 
The tip of the main jet should be 3/8 inch below the gasket surface of the bowl, and the cap jet should be 7/16 inch below the gasket surface of the bowl.
 
Thanks for the great information. I'm sure this will get the jobe done and am looking forward to trying them on my A.
 
170bdlx said:
I am rebuilding three carbs and need some advice about the main and cap jets. I see that both jets should be at the same level in the lower body at the narrowest point in the venturi. All three of mine are not when one washer is added tom each. The main jet is higher on all three carbs. It takes three washers on the main jet to make it level with the cap jet, then they are level and seem to be at the correct point on the venturi. Is this normal?
Click to expand...
Only one washer per jet!! Idle jet NO washer. Make sure there are not other washers in the seats.
 
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