Q-jet: what is this?
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
Q-jet: what is this?
I've been working on q-jets for years as a hobby, but I just noticed something for the first time today on the E4ME on my '81. On the driver's side of the airhorn by the secondary butterfly (directly opposite where the butterfly tension spring is) there is a small hole (about 3/16")going into the secondary bore just below the butterfly. It is open on my car and the car runs fine, but on the other half dozen or so q-jets I have on vehicles or in the garage, the hole is plugged by a metal ball (I knocked one out of a parts carb to look at it). None of my books say anything about this hole. My question is this; Is this hole supposed to be plugged on all carbs, or is mine correct with the hole open? It would be easy enough to put the ball I knocked out into mine, but I just wanted to ask first. Like I said, the car is running fine (maybe I shouldn't fix it if it ain't broke?). Thanks in advance, Sensei
Last edited by a1sensei; May 17, 2006 at 03:28 PM.
Melting Slicks
Joined: Dec 2004
Posts: 2,101
Likes: 3
From: Cruising somewhere in St. Louis, Missouri
Originally Posted by a1sensei
I've been working on q-jets for years as a hobby, but I just noticed something for the first time today on the E4ME on my '81. On the driver's side of the airhorn by the secondary butterfly (directly opposite where the butterfly tension spring is) there is a small hole (about 3/16")going into the secondary bore just below the butterfly. It is open on my car and the car runs fine, but on the other half dozen or so q-jets I have on vehicles or in the garage, the hole is plugged by a metal ball (I knocked one out of a parts carb to look at it). None of my books say anything about this hole. My question is this; Is this hole supposed to be plugged on all carbs, or is mine correct with the hole open? It would be easy enough to put the ball I knocked out into mine, but I just wanted to ask first. Like I said, the car is running fine (maybe I shouldn't fix it if it ain't broke?). Thanks in advance, Sensei
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
If your talking about the hole at about 7 oclock on the drivers side secondary butterfly, mine is plugged. It faces the drivers fender right by the bolt hole boss on the bore and opens into the bore just under the butterfly
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
Originally Posted by SIXFOOTER
If your talking about the hole at about 7 oclock on the drivers side secondary butterfly, mine is plugged. It faces the drivers fender right by the bolt hole boss on the bore and opens into the bore just under the butterfly
P.S. I'm sorry I have no way to post pictures right now.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Henry is correct - they run the drill through the casting from the outside, and then plug the outer hole. If the hole is not plugged at this location, it has no effect on performance.
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