Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: omarghazzy on September 29, 2018, 08:40:52 PM

Title: Mild 350 rods and jets
Post by: omarghazzy on September 29, 2018, 08:40:52 PM

Hey guys
Im sure this has been discussed before but I never found a straight answer

I have a 17084226 carb. Dont know who and when it was redone but it has a 73 with 50M rods with DA secondary

Its a bit lean on my 350 on primary circuit
9.5:1
Comp xe262 218 226 at 50
Edelbrock heads and performer intake

I Feels like a 73 with 50M thick rods 0.036 is a bit lean on the powe side
Can someone tell me if Im better off with 74 and 41k 0.026

Or how is this combo good enough

This is in a chevelle
And I read that M rods came on trucks
Not sure why

Other suggestion are great as well

Thanks

Title: Re: Mild 350 rods and jets
Post by: 77cruiser on September 30, 2018, 05:35:00 AM

How is it cruising at light throttle? You could step up to a 74-75 jet & a 52 M rod.

Title: Re: Mild 350 rods and jets
Post by: omarghazzy on September 30, 2018, 06:24:59 AM

Why M rod not K rod
Trying to wrap my head around this

Title: Re: Mild 350 rods and jets
Post by: Cliff Ruggles on September 30, 2018, 12:29:32 PM

Where is it lean at?

Idle, off idle, light throttle, heavy throttle, etc?

What makes you think it's lean, hesitation, stumble, bog, surging, etc?.....Cliff

Title: Re: Mild 350 rods and jets
Post by: omarghazzy on September 30, 2018, 01:47:33 PM

Hey cliff
It bogs if m doing light throttle then I push it half way to go up a hill or sth
Mainly on cold days if not fully warm up
It also feels a better when fully warm or its a hot day
Choke working file 5 min then fully open
Plugs are a bit too white
Thx guys

Is 73 jet enough for a fat 50m

Title: Re: Mild 350 rods and jets
Post by: Cliff Ruggles on September 30, 2018, 06:26:23 PM

Did you use the APT system to fatten it up at light part throttle?

Do you have full control with the mixtures screws at idle or is it lean there as well?

If it's fine when you push harder into it then the jet size and rod tip (.036") are adequate. 

It's difficult if not near impossible to read plugs with this new fuel but they should be very light tan to almost white.  Remember this is a Q-jet not some pig rich gas sucking Holley or Carter AFB clone.......Cliff

Title: Re: Mild 350 rods and jets
Post by: omarghazzy on September 30, 2018, 07:18:11 PM

Thanks cliff

I tried to pull the APT 8 turns up and its better on cold days

Idle screw I can close all the way and it wont die but I have it 2 turn out and its happy
Im not in the US so limited access to part
Old jet performance sticker on carb tells me this is a stage 2 so whatever mod they did to it

Is this a good carb knowing it came from mid 80s truck or should I find a 77-79 carb instead

Can I up the jet one size or to and keep this 50m rod

Thanks

Title: Re: Mild 350 rods and jets
Post by: Cliff Ruggles on October 01, 2018, 03:21:57 AM

Before you do anything check the power piston hanger arms to make sure they are EXACTLY even and level. 

I haven't taken one of those apart yet that were even and level......Cliff

Title: Re: Mild 350 rods and jets
Post by: 77cruiser on October 01, 2018, 04:12:03 AM

Cliff do you have a fixture to check them or the well trained eye?

Title: Re: Mild 350 rods and jets
Post by: Frank400 on October 01, 2018, 04:29:40 PM

Is this a single main air bleed carb ?

Title: Re: Mild 350 rods and jets
Post by: 77cruiser on October 01, 2018, 05:19:38 PM

Yes, it is I have one on my 421 sb that I did some major changes to just to see how it worked out. Originally was 72/50M I believe.

Title: Re: Mild 350 rods and jets
Post by: Cliff Ruggles on October 02, 2018, 02:12:33 AM

Yes, those are single main airbleed and use "M" series primary metering rods.  It should have plenty of fuel with 73 jets and 50M rods in a mild 350 application.  The trump card is being from Jet, so no telling what they may have done to it.

Pretty easy to get the power piston hanger arms level and even.  Pull the tips together and bend the arms if/as needed till they are exactly the same......Cliff