[tremo]

I have a sporadic issue whereby on start up I have an extremely rough idle where the carb is running very, very rich from the smell and from looking at the spark plugs.

Sometimes it evens out after warming the engine up. However, lately it's been getting worse, so I pulled the top off the carb and noticed that both primary metering rods were bent! I had this issue once before, but only one rod was bent. I straightened it out and reassembled the carb and it ran great....for awhile.

I'm thinking the bushing that holds the rods in place must have slipped up, the rods came out of the jets and then got bent? Anyone else seen this before?

I have a Q-Jet rebuild kit from Napa, and while it has what appears to be a cork-like grommet that's the same size, it doesn't include a plastic bushing like the original that I'm showing in the second pic.

I also poked around Cliff's /shop, but didn't see the bushing offered.

1) Is my assumption correct that the bushing is failing?
2) If so, where can I get a replacement?

Thanks!

Jim.

[carbking]

The better repair kits contain an aftermarket metal retainer to hold the original bushing in place. I would guess Cliff's kits contain this retainer, I know ours do.

No offense meant, but the most common cause of bent metering rods on a Q-Jet (if the retainer is not used) is failure to hold the piston in place when a new air horn gasket is installed. I don't think it is possible for a rod to come out of jet once the carburetor has been re-assembled.

Jon

[74Grandville]

someone probably tightened the Q-jet top without ensuring the rods were in the jets and held in by the collar.

your carb will run much better once this is corrected

[tremo]

@carbking - Ahhh!! No offense at all, thank you for sharing!

So, this may be a self-inflicted wound?! I for sure didn't realize I should use a "retainer". I ensured the piston was working before reassembly, but I didn't really hold it in place while putting the air horn back on. It's a challenge to get it all back together again with all that's required - 3 hands would have been best!

Live and learn. I will take a look tomorrow and see if they are bent again. Will also measure my primary and secondary metering rods on another related thread:

QuadraJet - Which secondary metering rod to use?

[Kenth]

Tremo, you need to relocate the inlet needle clip.

[Cliff R]

All of my rebuild kits come with a new retainer for the power piston.

https://cliffshighperformance.com/pr...rebuild-kit-sr

[carbking]

Originally Posted by Cliff R

All of my rebuild kits come with a new retainer for the power piston.

https://cliffshighperformance.com/pr...rebuild-kit-sr

Cliff - as do ours. I would have bet and given odds that your kits contained the retainer.

I know we started placing them in our kits 40 years ago.

You and I may have the only kits that contain these; which simply re-affirms that non-carburetor folks are doing bill-of-materials for the FLAPS kits.

Jon.

[Cliff R]

I don't consider a rebuild kit to be worth a chit without a new PP retainer. A secondary plastic cam also comes in all of my kits except the "basic" kit.

I'd like to have a nickel for every person who calls up here with secondary transition and performance issue right after "rebuilding" their carburetor and the FIRST question I ask them is if they replaced the secondary cam/spring?

I'd also mention here that almost 100 percent of the carburetors sent here with troubles have bent power piston hanger arms, and a high percentage of them came from a "builder" or shop someplace that supposedly specializes in them.

Most also have a power piston spring that is either "clipped" or looks like it cam from a ball point pen. They NEVER have the correct N/S assembly either, the main jets are either all worn out or drilled WAY too large, and..........I'll stop there or I'll end up writing a book on here about it!............Cliff

[unruhjonny]

I also want to chime in that those are definitely bent because of some bozo tightening the airhorn with the power piston not properly secured down.

It's really an easy mistake to make, but I have never opened a carb which had both bent!

[carbking]

Rochester and Carter seemed to work together in the 1960's; learning from each other's issues as well as successes.

Lots of Carter AFB step-up rods are bent because the step-up piston and rod are in the air horn, and Dr. Goodpliers would pull off the air horn to change the accelerator pump (which probably didn't require changing in the first place) then replacing the air horn with the rods still in place!

Rochester designed the Q-Jet with the rods in the bowl, eliminating this trick from Dr. Goodpliers.

Jon

[Ram Air IV Jack]

Originally Posted by Cliff R

I don't consider a rebuild kit to be worth a chit without a new PP retainer. A secondary plastic cam also comes in all of my kits except the "basic" kit.

I'd like to have a nickel for every person who calls up here with secondary transition and performance issue right after "rebuilding" their carburetor and the FIRST question I ask them is if they replaced the secondary cam/spring?

I'd also mention here that almost 100 percent of the carburetors sent here with troubles have bent power piston hanger arms, and a high percentage of them came from a "builder" or shop someplace that supposedly specializes in them.

Most also have a power piston spring that is either "clipped" or looks like it cam from a ball point pen. They NEVER have the correct N/S assembly either, the main jets are either all worn out or drilled WAY too large, and..........I'll stop there or I'll end up writing a book on here about it!............Cliff

This is exactly what you reported to me Cliff years back when I sent my 69 273 Qjet to you. A local buddy rebuilt my Qjet but it never ran well and always stalled at idle. He tried many times to adjust it with a vacuum gauge but it never ran well. Then someone local suggested a carb shop in Onterio California so I called them in the winter months. I sent it out there for a total rebuild where it was colored and sent back, looking like an NOS carb. It ran well on my RAIV motor but it needed service years later and then I contacted you. When you reported all the issues with my Qjet, I couldn't believe it, especially the missing primary metering rod spring that cause vibration and wore the jets oblong! That shop is no longer in business but still many people claim to know how to rebuild these carbs but in reality, they don't and you get burned!

[tremo]

Let me close the loop from my side...

I pulled the carb again after it was still running rough and the primary metering rods I had previously straightened were working perfectly. So, the bushing did not pop up during reassembly as I was thinking.

Instead, the two brass rods as shown marked in tape fell out of the air horn and were laying in the fuel wells! Geeze-Louise, if it ain't one thing, it's another! They seem to be a "press fit", so I reinserted them "strongly" back in their proper place, put the carb back together and she's been running great since last Friday! She idles so smoothly now.

Not sure how those managed to work themselves loose when I tried very hard to ensure the air horn was on a proper stand and not laying on it's side.

Glad it's fixed. Thanks for all the feedback!

[Cliff R]

Those are the pick-up tubes for the secondary POE.

They have NOTHING to do with it "running rough" and are only there to supply fuel to the secondaries when you go to FULL THROTTLE. You could leave them completely out and about all that would happen is a momentary stumble/hesitation/bog when you go to full throttle.

I also noticed another potential problem. Remove the secondary hanger and metering rods BEFORE putting the top back in place. You will destroy the secondary fuel supply discs, the rod tips and bend that hanger too. The hanger and secondary rods go back on after the top is back on the main casting.......

[tremo]

Thanks Cliff, your insight is much appreciated!

What's weird is that it truly was "cause and effect"' as I only put the pick-up tubes back to in their proper place and put the carb back together and it's run fine ever since. i.e. No "rough idle" and it performs excellent at WOT. Very odd. Perhaps a red herring? Well noted about the secondary hanger and metering rods! Live and learn....