Guess what I get to do.

-

TrailBeast

AKA Mopars4us on Youtube
Joined
Mar 11, 2011
Messages
22,958
Reaction score
13,101
Location
Arizona
Give you one guess.
I picked up this like new Holley 770 vacuum secondary Street Avenger for 100 bucks because the previous owner said he could never get it to work right.
Well for one, the cap for the secondary vacuum pod wouldn’t seal because the powder coating stopped it from seating where it’s Oring could contact the body.
Filing down the surface on the under side of the cap fixed that.

Next was that the high idle arm was under the choke linkage when it actually goes over the top of the choke linkage rod.
That caused the choke to only open about 1/3 of the way, and high idle cam to never work at all.

A few jet and low speed air bleed adjustments later and I have been very happy with how this carb works.

The other day I smelled raw fuel in the driveway and checked all the fuel lines and connections.
I have 3/8 nylon 12 efi line as a main feed as well as the return, and I was expecting to find a fitting seep or small crack somewhere. (Nope)

I finally found it.
The lower passenger side secondary float bowl screw was leaking.
This is the kind with the nylon sealing washers.
I went to snug it up a little and found it wouldn’t tighten up at all.
Stripped dammit.
After checking all of the others I found two more stripped.
WTH???
None were ever stripped before, and now 3?

Ok then, FINE. :D
I am totally capable of doing this.

So, what do you think caused this for no apparent reason?
I’m thinking too tight to begin with, and heat expansion maybe?
I guess from now on they are going to only get snugged up enough to not leak, and then periodically checked.

IMG_6028.jpeg


IMG_6029.jpeg
 
PO handywork I expect. Doesn't take much torque at all. I make new, reusable plastic washers from coffee can lid plastic. The fiber washers like to shred.
 
Greg I sure don't know, but I will say that the older Holleys I've worked on DID NOT USE "standard" thread screws. They were all oddball, sorta like guns, if you are familiar. So I'd guess you'll need to come up with "alternative" screws in order to repair/ retap/ helicoil the bad ones.
 
I can’t imagine enough heat getting to the carb body to expand/contract enough to pull the thread out of a hole.
 
Looks like the thread size is 12-24. There are several different types of washers for the float bowl screws. I like the "sammich" style. Like these:

 
Last edited:
Greg I sure don't know, but I will say that the older Holleys I've worked on DID NOT USE "standard" thread screws. They were all oddball, sorta like guns, if you are familiar. So I'd guess you'll need to come up with "alternative" screws in order to repair/ retap/ helicoil the bad ones.

Looks like the thread size is 12-24. There are several different types of washers for the float bowl screws. I like the "sammich" style. Like these:

[/URL]

I did quite a bit of research on this and found the screw threads are indeed 12-24 as is the heli coil kit.
The drill size used is just a bit larger than the original threads, so I am pretty comfortable with the whole setup being the right setup.

Thanks guys.

Rusty, I kinda like the old school style washers as well.
I have a Holley Trick Kit that I can check for those.
 
I did quite a bit of research on this and found the screw threads are indeed 12-24 as is the heli coil kit.
The drill size used is just a bit larger than the original threads, so I am pretty comfortable with the whole setup being the right setup.

Thanks guys.

Rusty, I kinda like the old school style washers as well.
I have a Holley Trick Kit that I can check for those.
Yeah the ones I posted are the thick ones. They don't tear near as easily. A little cheap stick on both sides usually keeps them from sticking.
 
Yeah the ones I posted are the thick ones. They don't tear near as easily. A little cheap stick on both sides usually keeps them from sticking.

Chap stick :D

Yup, the thick ones are what I had in mind.
Always hated how the thin ones tore leaving some of it stuck to the bowl.
 
I don't know whether I'm old enough to remember, or gotten old enough to forget....................

Boy do I hear that.
I frequently wonder what I don’t remember.

BTW, the carb body thread repair went perfectly.
I used my drill press to gently drill the holes so I could be sure the holes were true.
Tape over the body surfaces kept shavings from getting in all the exposed passages.
Then took the belt off the drill press drive and chucked up the tap, then ran the tap in a few threads turning the chuck by hand then finish the tapping in the house.
After rinsing and blowing the oil out of the new threads in the carb body I installed the heli coils and finished assembling the carb.
I could have installed it back in the car today, but decided to put it back together tomorrow morning when there isn’t a 35mph wind like today.
The engine is covered till then.
 
OK, first, the fact that Holley makes those thread inserts tells mee that it is a known problem. So why not fix it.
Second, and you guys asked for this mentioning Chapstick:
A tough looking cowboy rode up to a saloon and tied up his horse. Before he walked into the bar, he lifted the horses tail and kissed it right on the butthole. When he walked into the saloon, the bartender said, "I couldn't help but notice that you kissed you horse right on the butt. Why do you do that?" The cowboy said, "Chapped lips." The bartender said, "Does that cure them?" The cowboy said, "No, but it makes you think twice before you lick your lips."
 
My guess is someone over torqued them or maybe used an electric impact not knowing any better .
 
So I take it you think a 1/2 impact is too much for a 12-24 bolt in aluminum threads?
Ha ! Lol
We had a tech at our Acura use an impact to reinstall a drain plug on a trany . Split the case ! His last day ….
in this case it may have been a 1/4 drive battery powered impact used by someone that had no mechanical aptitude .
 

I drive a Zamboni now at a local hockey rink . The first time I was involved in changing the blade they freaked out when I used the 1/4” drive impact to remove and replace the 1/2” stainless steel countersunk fasteners . This blade is a 6” long 6”x 3/4” hardened steal !
I couldn’t convice them that the 1/4 shaft on the little impact would shear long before the 1/2 SS bolt .
Not to mention Zamboni could not provide torque specs for the fasteners…. Just said “ yea tight “. …
 
Ha ! Lol
We had a tech at our Acura use an impact to reinstall a drain plug on a trany . Split the case ! His last day ….
in this case it may have been a 1/4 drive battery powered impact used by someone that had no mechanical aptitude .

I’ll just say I have never broken someone else’s car, and leave it at that. Lol
 
Yeah, it's not like it takes Mandingo torque to tighten the float bowl screws. I very lightly tighten them, run it a few heat cycles and come back and lightly tighten them again.
 
Ha ! Lol
We had a tech at our Acura use an impact to reinstall a drain plug on a trany . Split the case ! His last day ….
in this case it may have been a 1/4 drive battery powered impact used by someone that had no mechanical aptitude .
I only recently, before the house fire, acquired more than a couple of those 1/4 hex impact drivers used, thrift stores, Marketpharce. I was AMAZED that at least a couple of them will develop something on the order of 50 ft lbs!!! I don't know why the hex does not break!!! I tried it on the diesel. You can rattle the lug nuts on tight enough that I would not be afraid to drive it a short distance.
 
My 1/4" Matco Li gun can rip a 5/16" bolt in half w/a full batt., no problem....
 
I only recently, before the house fire, acquired more than a couple of those 1/4 hex impact drivers used, thrift stores, Marketpharce. I was AMAZED that at least a couple of them will develop something on the order of 50 ft lbs!!! I don't know why the hex does not break!!! I tried it on the diesel. You can rattle the lug nuts on tight enough that I would not be afraid to drive it a short distance.
Yep.. 55 ft-lbs depending on how the charge is . We broke many installing lifts but that was due to wrong angle while drinving 3/4 inch treaded concrete anchors .
 
-
Back
Top Bottom