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Old 10-01-2016, 02:21 PM   #156
davepl
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Join Date: Aug 2006
Location: Redmond, WA
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Re: Diagnosing a misfire

Quote:
Originally Posted by Mrturner1 View Post
I just watched a video on tuning Holley carbs with long duration cams and I have a MUCH better idea of what's going on inside the carb. I'd be willing to bet that my transition slot is showing way to much but I'll have to confirm tomorrow when it's light outside. The guy on the video showed a way to close the throttle blades a bit by drilling small holes, which allowed him to close the throttle blades exposing less of the transition slot.
I've done that... once. Actually I didn't do it, it was done to my carb by someone I figure knows what they're doing, but I still am not sure it was the right approach. That was for a ZZ502 with a Q-Jet.

I think 99% of the time when people want to start drilling holes in throttle blades to get them to close further so that they can uncover the transfer slots they're actually band-aiding some other problem, like a vacuum leak that they don't know about.

And 1% of the time it's actually the right fix... but I think it's uncommon.
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