Setting up the new carb--pointers?

[F250 Restorer]

I haven't run it since I drilled out the mix holes.  If backing out the mix screws has no affect on the surging/nozzle drip, should I drill the restrictions in the idle tubes, or just purchase diff. ones from you. 

If I should drill, what would be the size of drill to use? 

[F250 Restorer]

I wanted to mention that since I plugged the bypass air in the throttle plate I have had to turn the idle screw in quite a bit to get it to idle.  That means the primary flaps are open a bit, and, I imagine that is what is causing the nozzle drip and surging. 

Where do I go from here? Thanks, Cliff.

[F250 Restorer]

A Happy and healthy Easter to you and yours, Cliff, and to all others on this forum.

I didn't hear from anyone, so I went ahead and read through the modifying section of the book. Since I no longer have by pass air, I guessed that the stage 1 recipe would be too little for my carb.  I hope that was correct.  I drilled the idle tubes at .045".  I wanted to enlarge the down restriction too, but found it to be considerably larger than .045", so I left it.  I will try it tomorrow and see how it fares. 

[F250 Restorer]

Cliff, what size should I drill the idle tubes at?  Where would you start?

[F250 Restorer]

After sinking about $300 into this project, I do not want to give up on this carb.  I found a diagram online that really helped me 'see' the idle system and understand how it works.  I want to post it here to help anyone else who is struggling. 



I spoke to Cliff and he is as perplexed as I am.  I'm sure it is b/c of my lacking knowledge of carburetors.  But when I install once more I will do the tip in again.  If the engine sp increases, it needs more fuel.  If I pull a v.line and the engine sp. increases, then the carb needs some by pass air. 

[F250 Restorer]

After sinking about $300 into this project, I do not want to give up on this carb.  I found a diagram online that really helped me 'see' the idle system and understand how it works.  I want to post it here to help anyone else who is struggling. 



I spoke to Cliff and he is as perplexed as I am.  I'm sure it is b/c of my lacking knowledge of carburetors.  But when I install once more I will do the tip in again.  If the engine sp increases, it needs more fuel.  If I pull a v.line and the engine sp. increases, then the carb needs some by pass air.

My next question is regarding nozzle drip.  I found online that a rebuilder says diff. QJ's have the main discharge nozzle protruding into the air stream diff. amounts, and he states the ones protruding more suffer from the drip.  He recommends tapping the nozzles deeper into their housings.  Could you please respond to this? 

Also, regarding the drip: Although my engine is a 300 I6, the head is ported and larger valves have been installed, allowing it to breathe well.  It also occurs to me that the runners in my intake are divided top to bottom for a double plane intake.  The primary side of the carb gets 1/3 of the runners.  With larger valves, the air must be moving at great velocity.  Is the greater velocity adding to/creating the drip?  Should I therefore use the open base gasket so the full runners are used, thus dropping the velocity of the air, creating less pull? 

[F250 Restorer]

I am having difficulty.  If I had a customer having problems, I would go out of my way to help them, especially if I were trying to build my business.  Don't you think that a simple 'do this, then do this' would be in order?  But instead, I am ignored b/c I am lost.  How helpful.

The bottom line is this:  I can take an engine apart and rebuild it. I have successfully rebuilt several carbs.  But, like many mechanics, I get lost with the QJ, hence the nicknames for this carb.  After studying your book for more than two weeks, and working for about two weeks on a QJ, and spending about $300 on the rebuild, I can not make sense of it, and, my posts are ignored by Cliff.  That is what my article will reflect--the truth.  And, that is what I will say on the forums. 

When it was time for me to buy something, I got your time.  From then on I got a fleeting response on your forum. 

I will resolve this on my own.  Now I understand why this carb has such a poor reputation.

[Cliff Ruggles]

I've went over the entire thread several times, and provided some advice over the phone in between. 

The diagram provided is not even one of your model carburetor, but a much earlier design with direct upper idle airbleeds.  It also shows a "fixed" idle bypass, and off idle port, not a transition slot like your unit uses.

The last time we spoke, I provided two test methods for you to use, to determine a course of action. 

Pulling a vacuum hose will mimic adding more idle bypass air.  If you have enough idle fuel at the mixture screws, then you can slow the idle down, re-adjust the screws, and get off the main system.  All that would be needed at this point, would be to add a little bypass air, leave everything else alone, and start enjoying the vehicle.

A rich idle conditon can be simulated by tipping in the choke flap, or gently placing your hand over the top of the carburetor.  If it wants/needs more fuel, it will smooth out nicely at idle speed.

I'm not ignoring anything, just waiting for results from the testing/modifications to see which way you need to go?

I can't crawl thru the computer screen or thru the phone to correct the problems.  Like I told you over the phone, if the carb were here, I could get it dialed in less time than it took to type this.  I suspect that you don't have enough fuel to the mixture screws, which has the throttle angle too high to sustain idle speed to a point where it's starting to pull the fuel it wants from the main system.  No way to confirm this without a few basic tests, as we discussed over the phone, and I haven't seen or heard anything about that since, just a picture of a very early unit on the website, with no questions in either thread.

There is no one in this industry to goes further to help folks out than I do.  At least 30 percent of my work load is fixing carburetors and helping folks out who spent money elsewhere.  Buy all your parts at NAPA, or from another vendor, and see if they even have a website to answer questions, or even care if you get a good end result or not?......Cliff