Topic: 74 550 f carb problems

[74550pa]

i have a 74 550 f that is giving me a fit. I bought it after it had been sitting for years. I rebuilt the carbs because they were really dirty. when i got it running it runs fine with the choke, but when I turn the choke off it idles real fast then dies. i took them apart again and recleaned everything.still the same. I checked for air leaks with carb cleaner while its running,but did not find any. does anyone have a cluE this thing is making me nuts!!!!!!!!

[joeb]

Did you bench sync your carbs. And are you getting fuel to the float bowls . Just a thought.?? 

[TwoTired]

You have to clean things you can't see, too.
It still sound like your idle circuits are plugged up.

The idle circuit has four openings into the carb body: The idle jet, the air screw hole, the air jet hole, and the delivery hole into the carb body.  You need to verify that fluid will travel from each hole to every other hole.  Sometimes the passageways corrode and block a pathway.

Did you take out and clean the emulsion tubes behind the main jet?  These get pushed out from the slide needle end.  The brass tube has small cross drilled holes that must be cleared.

How did you vacuum sync the carbs?

Cheers,