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Yes they are. I cleaned everything out several times and put the carb back on. I ran out of time so I'll start it in the morning. I didnt find anything clogged so I'm not optimistic.
Does this Holley have replaceable bleeds? if so try going up a couple of sizes on the HSAB to see if that helps to start the mains slower. Also one guy on another site that had your problem had a bad metering block gasket to the main body that fixed his booster dribble.
 

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You really need to soak the parts overnight in a gallon of carb cleaner like this. it also makes all the old gasket material fall off.

You have to be careful with that stuff, I soaked 2 metering blocks overnight one time and it literally took off all the bronze coloring on them. Sucked too as they were from a super rare 4788 Corvette Holley. 1 hour is plenty with that stuff IMO.
 

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70 Chevelle, 489 BB, Jerico DR4
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Discussion Starter · #24 ·
Before you put it on did you check the transfer slots?
I did, it was a little over square but probably acceptable. The mixture screws were responsive and the engine would die quickly at about 1/2 turn out if I remember correctly. It died fast. I couldn't turn the screw out quickly enough. The secondary was opened slightly more then the instruction preset. So I squared the primary and opened the secondary an equal amount. The secondary is not even close to exposing the slot. I'm making 10-11 inches of vacuum. I may drill some holes in the throttle blades. The plugs must have fouled because it would not start yesterday. I'm going to change plugs shortly and see if anything's changed and recheck mixture screws for responsiveness.
 

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Discussion Starter · #25 ·
You really need to soak the parts overnight in a gallon of carb cleaner like this. it also makes all the old gasket material fall off.

Well I did use it but not overnight. Maybe I'll give it another try. That stuff is not the same as it was back in the day. It use to stink horrid and work amazing. I spilled some once in and you could smell it for years after. The new Democrat version is not the same.
 
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Discussion Starter · #26 · (Edited)
Does this Holley have replaceable bleeds? if so try going up a couple of sizes on the HSAB to see if that helps to start the mains slower. Also one guy on another site that had your problem had a bad metering block gasket to the main body that fixed his booster dribble.
No it's just a standard 850 4781-5, but as you say maybe my problem lies elsewhere? Be nice to see a picture of that bad metering b lock gasket.
 

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Discussion Starter · #27 ·
Use carb cleaner. Brake clean is different. Protect painted surfaces. If you are not concerned about having a pretty carb, you can get cleaner in gallon cans and let parts soak overnight.
2000 rpm is off the idle circuit. Focus on the main circuit as mentioned above. Look at the gasket impressions on the meetering plate and follow the flow of air and fuel.
You probably just sucked some debris from the tank and it is stuck in the small internal passage.
What filters do you use?
 

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Discussion Starter · #30 ·
I have had leaks using things with summit AN fittings. Even with teflon tape. Use Fragola now and no leaks.
I'll look into the Fragola, sounds familiar. I just changed plugs. I'm going to fire it up in a minute. If the booster is still dripping I'll pull it off and take pics of the transfer slots.
 

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Before install.Write down front and rear main jets, pump cam and which hole is the screw in, power valve, power valve restrictors, air bleeds at the top of each bore. Adjust floats, accelerator pump. After running and you adjust idle screw on the linkage do not forget to check accelerator pump.
 

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If anything - please, please - put a nut on your carb stud so it does not wiggle around like that. Let me tell you how it plays out. The stud will vibrate loose and over a period of time come undone and go down into your intake into the cylinder and take your motor out (Massachusetts Avenue by American University - May 1983). You might notice a slight iregularity in your carb as the stud goes past the throttle blades a mile or so before this happens. And that is not normal you need to look into your carb like the other guys said above.
 

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Discussion Starter · #34 ·
Before install.Write down front and rear main jets, pump cam and which hole is the screw in, power valve, power valve restrictors, air bleeds at the top of each bore. Adjust floats, accelerator pump. After running and you adjust idle screw on the linkage do not forget to check accelerator pump.
Well the saga continues, no change. Mostly stock carb calibration.😁

80 jets front and back, 4.5 PV front and back, 30 cc pump primary factory pink cam screw position one, 50 cc pump secondary position one, factory brown cam screw position one. Both adjusted after setting idle front and back.

Air bleeds are non replaceable and look unmodified.

Mixture screws run best at one turn to one and 1/4 turn out. Very sensitive and stalls at anything less then 1 turn out. Autometer gauge reads 11 inch vacuum and stable. Harbor Freight gauge reads 8 and bouncy +/- 2


I'll post some pics shortly. Thanks for the help(y)
 

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Discussion Starter · #35 ·
If anything - please, please - put a nut on your carb stud so it does not wiggle around like that. Let me tell you how it plays out. The stud will vibrate loose and over a period of time come undone and go down into your intake into the cylinder and take your motor out (Massachusetts Avenue by American University - May 1983). You might notice a slight iregularity in your carb as the stud goes past the throttle blades a mile or so before this happens. And that is not normal you need to look into your carb like the other guys said above.
Thanks and good call on the carb stud. It's still tight but I won't do that again.
 

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Discussion Starter · #36 ·
Before install.Write down front and rear main jets, pump cam and which hole is the screw in, power valve, power valve restrictors, air bleeds at the top of each bore. Adjust floats, accelerator pump. After running and you adjust idle screw on the linkage do not forget to check accelerator pump.
See my previous post on specs. Here are some pics
Composite material Machine Nickel Household appliance accessory Metal

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Gas Machine Engineering Auto part Nut
Automotive tire Auto part Gas Metal Machine
Gas Rim Metal Automotive tire Auto part
Automotive tire Bicycle part Rim Gas Auto part
Wood Vehicle Machine Auto part Metal
Bicycle part Motor vehicle Gas Machine Auto part
 

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Pull your oil dipstick and smell the oil on it for fuel smell. In the 1980's I bought a polished Holley 750 dp. No matter what I could not get it right. Holley said send it back. Still not right. I smelled gas on the dipstick. Drained oil and it pored out like water. Rebuilt engine for piece of mind. Put the old 750 back on and sold the new one. Every person on here has had issues with lots of things. This is how we learn.
 

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No it's just a standard 850 4781-5, but as you say maybe my problem lies elsewhere? Be nice to see a picture of that bad metering b lock gasket.
Take a straight edge and check you main body for flatness in the metering block face. I had a 750 that was over .009 warped and after I filed it flat the carb worked a lot better, but I had some other issues with that one.
 

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Do you know anyone with a good ultrasonic cleaner ? Thats what I have been using on carbs lately. It doesnt make them real pretty but seems to get all of the internal passages good and clean. Any chance one of the throttle blades is bent a little getting it up into the main circuit at that point ?
 
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