webers popping on spider

["Phil Williams" <willamp@domain.elided>]

TMurray845@domain.elided wrote about about his webers popping through the intake
most anytime except during hard exceleration.

 I ran into a similar situation when I put 40mm webers on my '76 spider. My
popping was quit severe and occured as the throttle was taken just off of
the idle position. The problem would stop if the throttle pushed a little
further but this would always produce acceleration so you couldn't run at a
steady speed without the popping. When the throttle is taken just past idle
the main idle circuit kicks in and runs until the main jets takes over. This
appeared to be my problem area, the main idle circuit. The condition
appeared to be a symptom of a lean mixture from the main idle jet. I went to
the next richer idle jet and it resolved the problem. 
 To clarify, when the throttle is closed the main idle circuit is not used
and the bypass (with the adjustable mixture screw) is supplying the fuel. As
the throttle plates are opened the bypass circuit looses vacuum and the main
idle jets take over. Further opening of the throttle plates stops pulling
fuel from the idle jet and begins to use the main jets. Popping through the
carbs is an indication of a lean mixture. The throttle position when it
occurs indicates which circuit has the problem.
 

Hope this helps

Phil Williams
3 spiders and a platinum




_______________________________________________________
Get your free, private email at http://mail.excite.com/

------------------------------