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Holley tuning troubles.


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Ive installed a holley 5210 on my '82 BRAT. After first installing it, it idled at 1200 rpm no matter what. I used some copper tubing and rebushed the throttle shaft, and was able to get the idle down... But I cannot tune it! It will not idle consistantly. Sometimes the acceleration is great other times it bogs sputters etc. I have a number of jets and air correctors I've played with. Ive changed the idle jets up and down. Sometimes it wants more fuel, then after I have it running great its too rich, so I lean it out a bit, and its great, then it dies. I put a different carb on, and now it wont idle less than 1200 rpm again but accelerates fine. I know these rebuilt carbs are junk, but I have a bunch of holley 5200 pieces/parts around.

New fuel pump + filter 3psi fuel pressure +/- a hair.

I have checked 300 times for vacuum leaks. Everything is now plugged including brake booster. I have also sanded the adaptor plate and base of carb flat. Sprayed carb cleaner all over the place, nothing.

The cat is only 3 months old.

Gas looks fine, recent fill up... Could it be bad? I started thinking mabe that little coolant port under the carb adaptor was leaking (long shot) so I popped off my radiator cap to check the level, and I found foam/bubbles. Could a bad head gasket be screwin' with me? Car does not over heat. Ive had enough for today, any Ideas?

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I Really Don`t know much about Holley Carbs, but I Think that if it Idles and then Dies, maybe -Just Maybe- it could have an Stickin` Float Level; Also it could be caused by improper Air Flow by the Possibility of Dirt gettin` inside the Jets... Even if they`re Just Cleaned, maybe some Dirt went inside from Hidden Spaces / Old Gas inlet Hose... You can Spray Carb Cleaner there...

 

Good Luck!

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Ive set the float level about 6 times and changed the float to a plastic one from the brass. The only contaminants I had in the bowl were little brass shavings either from changing the jets, or I did find a really screwed up emulsion tube. I cleaned the carb out 2 times and replaced the tube. It ran ok for a while... I then decided it was full of brass shavings, and put on a different carb.

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I agree, thats why I didnt get too far in tuning it I was stuck on the idle system for ever. But I tried a 40-50-55-80 idle jet and with some tuning it would run fine but after a trip up and down the street it would start idling low and crappy and bogging and studdering under half throttle. Light throttle was fair. Floored was pretty good. Even changing the jets had little influence on this. I took to choke off the second carb, and plugged the element cooling hole. It is not a feedback verson of the 5210.

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Your homade throttle shaft bushing with the copper tubing is almost certainly to blame. Each time the plate closes it's slightly different and even minute changes in the airflow will cause big changes in idle tuning. Your acceleration problems are similarly linked to the throttle shaft play and improper setting of the transition port against the plate. The port must be dead center of the plate or it will be rich or lean at idle and will not transision properly.

 

Either have it properly reamed and rebushed by a machine shop, or get a new carb. You'll tear your hair out till you do.

 

GD

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The copper tubes replaced the rebuilder's bushings (ac delco) isnt likely taking it anywhere will help. Its pretty hard to find a good carb shop here. And even harder to find throttle shaft bushings.

That may explain why the unit I "ghetto bushed". But the second carb I put on does drive better. But I cannot get it to idle less than 1100 rpm. This carb is used though, but in good shape. My transition port is a slot.

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But I cannot get it to idle less than 1100 rpm. This carb is used though, but in good shape. My transition port is a slot.

 

Make sure the plate is closing fully and that there are no burrs or other damage to the idle jet and that it fits well into the holder, etc. Not idling back should be a simple thing to diagnose - you are getting air and fuel from somewhere. Either the plate is not closing or there's a problem with the idle jet or the transition slot is too exposed below the plate. You have to carefully set up where the plate lands when you put the carb together or it just won't idle or transistion properly. The trans. slot should be fully above the plate when it's closed.

 

GD

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http://www.surpluselectron.com/aaron/holley.htm

http://www.carburetorfactory.com/expvw17.html

http://www.mazdatruckin.com/B2200/5200.html

 

I used to have a bunch of sites on these, but I deleted them now that I have an FI sube.....

 

 

I sounds like it's too rich, or the throttle plates are open too far.

I've used a Holley 5200 before, set it up with the proper jetting for a weber, and it was fine. With the larger carb, you may need to adjust your timing too. Did you install a fuel pressure regulator? I think they like 1.5 psi.

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I have 3 carbs that can be functional. 2 of them have the 2 small hole set up for the ports. On both of them the ports are completely covered by the butterfly. Weather it leaked at the shaft or not, it definately has a small gap from the reemed out shaft on each side of the butterfly, which is probably the source of the problem.

I just put on the 3rd which is not rebuilt and has not been rebushed, has the slot setup. The idle screw can be adj. till the engine stalls. But, the idle jetting on this unit is not adjustable, and its too rich.

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I did remove the brass plug covering the mixture allen screw. But the plug covering the idle jet port I am afraid to remove because Im not sure there is anything behind it. Its pretty hard to remove those without ruining them. I dont think the idle jetting can be modified on this unit. There are soo many variations of these carbs, and the rebuild quality on them is pretty poor. I wanted to make use of these because I had a couple.

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G.D. was right on track.

Bore of the carbs/throttle plates are the source of my troubles for sure. I held the bores up to the sun with the plates closed tightly. The 2 factory reman ones no matter how hard I try I cant get light to not peak through just a tiny bit when the plates are closed. The J-Y unit I tried all 3 plates in it and with just a little adj. and a couple blips all 3 center perfectly and allows no light to creep through. This must just be a wear factor, and or a problem with the bushings. On a 2.5l motor I bet this small imperfection may not be as big a deal, but on these little motors its just screwing me all up.

Moral of the story. Facotry REBUILT carbs are junk. The things I found wrong with these, throttle shafts have excessive play after rebushing. One of them had a mangled emulsion tube. They obviously had trouble with it at the shop and just let it go. One of them was missing the idle jet. The holder was there but no jet... For anyone searching for info Holley 5200 5210 6500 etc, it is the luck of the draw as to what you will get. Save your money and time get the Weber kit or fix the Hitatchi.

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I had been looking for a F.I. set up at the J-Y for some time, I just gave up and decided to go another rout. For the time and energy lost I could have had the F.I. system running by now. For the money it will cost to convert to a new Weber I would way rather have F.I.

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  • 2 weeks later...

I have had this problem before as well, getting "factory" remanufactured carbs and having problems with them (such as the loose throttle shaft bushings and "mangled" emulsion tubes..This seems to be fairly standard in 'reman' carbs, though I've seen it mostly with the Hitachi carbs ( I did a lot of Suzuki work) I guess a product of my personal experience..

 

GD has a very good point... for the money you'd spend on getting your carb'd setup up and running, you could very well have a decent FI going in your favor... Do you have anything against going electronic? (I only ask, cause there are some "ALL CARB" devotees out there...)

It may be more worth your time and money to convert to a Fuel Injected system, and this could definitely save you a lot of time and hassle in the long run....

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