With trucks evolving faster than a clean freak can go through a gallon of quick detailer, some of the basic mechanical skills are getting pushed back into the memory banks. Things like plugging in a flash programmer to adjust the fuel tables is replacing buying a used Holley Carb and rebuilding it. This issue is dedicated to the classic truck and the components that make them run. There are a few different companies that make carbs, but Holley has found its way on to just about every used truck we have ever purchased, and the 650 Double Pumper we are rebuilding in this story is no exception. This Holley was resting atop Mike Finnegan's tired small-block in his '67 C10 and had a few little problems. The truck not only sputtered a bit off idle, but during a heavy foot-load of pedal the truck would seem to run out of gas. We were thinking it was a bad filter or something clogging the fuel line, until we got the sucker apart. Someone had rebuilt the carb previously and did a mediocre job, to say the least. They forgot the trim off the tip on the rubber umbrella check valve, which prevented the float bowl from going all the way down when the fuel got low. The needle and seat could fill the bowls but not fast enough under heavy acceleration, because they couldn't open all the way. This little oversight kept the carb from functioning to its full potential, and in turn, made the truck a pig to drive.

We took it off and inspected the throttle shafts to see if there was any amount of play in them, which there wasn't so this one qualifies for a quickie refurb. If you can grab the throttle and wiggle it up and down, you might want to pass on buying that one or send it out to a professional shop to have a bushing put in to the main body to tighten up the shafts. We ordered a simple rebuild kit from Holley and grabbed a few cans of carb cleaner and a can of gasket remover. There are a lot of things to learn about carburetors and how to tune them, which we will go over in another story at a later date; this one will outline the simple steps to rebuild the right way with minimal tools.

To Buy Or Rebuild, You Decide:

Used Carb Average $75 (eBay)
Rebuild Kit $34
Gumout $4
Gasket Remover $5
Total $118
New Carb $330

Step 1: The Teardown
Holley offers two different kits; one is a basic rebuild kit that has all the gaskets, power valves, accelerator pumps, and other service parts to do a rebuild. The second is a trick kit that gives you everything the basic kit comes with, along with a bunch of tuning parts to adjust for different motor and cam selections. Ours will be going on a stock 350, so the trick kit is not necessary. Depending on what you need your carb to do will dictate what kit to buy, and if you are not sure, call Holley's tech line and they can lead you in the right direction.
Additionally, before ripping into the rebuild, it's a good idea to have a few little containers to hold small parts. And, if you are real serious, there are many books written to help you along the way.

The Final Word
With everything tight, we slapped the freshly rebuilt Holley on our test-mule motor for the next dyno day. We will go over how to set everything up on a running motor in another story, so until that time happy wrenching.

SOURCE
Holley Oil Eater
www.oileater.com
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