Holley adjustments

[v-mad]

I fitted a Holley 1848-2 (450 CFM) a while back. It seemed to work fine to start with, but recently it has been running rich and fouling the plugs.

So I reset the float levels and cleaned the plugs, and it seems to run better now, but things are not quite right yet. Normal driving is fine but there is some misfiring near idle.

When I set the idle mixture screws, one side responds normally to adjustments (best idle at about two turns out) but the other (right hand) side screw has no effect. This suggest that the right hand side is getting fuel from somewhere it shouldnt.

I dont want to strip the carb down unnecessarily, but I cant think of anything else I can do. Any suggestions please?

[anonymous]

I spent the better part of two years fooling with a Holley carb. Set the floats, idles well. Go for a ride and the fuel would be gushing into the motor. Back to the garage, reset the floats, idles well, go for a ride and the motor would be starving for fuel.

These "rides" were about two blocks long.

Switched to an Edelbrock #1404, set the idle screws and took a 400 mile trip. That was 11 years ago and I haven’t touched the carb since, though I should probably rebuild it.

No power valve to screw up. Springs and needles are changed without a teardown of the carb, just remove the top plate.

You couldn’t pay me to use a Holley.

Fred Baum
An Edlebrock fan for life.

3

[Jeff Nichols]

I put an Edelbrock carb on my car way back in 19 hundred and 96. And by God, it’s been touched less than a virgin in a monastery.

I can’t count on both hands and feet , how many times I’ve been told that Holley carbs are the "real ones" to use. All I know is that Holley carbs are the ones who always seem to need adjustmnet.

[v-mad]

I have heard many accolades for the Edelbrock, and if I was buying new I would also, no doubt have gone down that route. But I got this one off ebay for a song, and it looks like new; very clean and un-messed with. So I decided to persevere for a bit. Also its a 465 CFM which in theory is better matched in size to the 260 engine than a 500CFM.

I got a reply from Gerard on the ‘bob2000.com’ website (that someone here recommended) and he confirmed he thought there was a blockage.

So this morning I took out the right hand idle screw and blew out the carb with compressed air a few times. After I had put back the screw, and set both sides at 2 turns out, I restarted the car. Eureka! Problem solved; I have shifted the blockage, and saved myself a carb strip down.

I think Holleys are good once they have been set up properly, and do run reliably for a long time. But if you have to fix or tune one up, they do have a reputation for being difficult to work with.

But for today, maybe Holleys reputation is restored a little eh?

[anonymous]

In my mind Holleys are still no good. Mine was new out of the box and it still did not work.

One should not have to fool with anything new out of the box, except to adjust for individual preferences and idiosyncracies of the application.

Fred

2

[Bud & Donna Elliott]

The first Holley I bought was "New" thru Ebay $150. What a piece of crap. The second Holley I bought was new from a local parts store at about $300. Another piece of crap but better than the first. Bought a new Edelbrock 500 for $200 , bolted it on the car, set the idle and drove off into the sunset. The carburetor for people who hate to mess with carburetors.

The car is just as fast and maybe even faster. Starts better hot or cold, cold idle is better, everything is better. If you need a Holley 1850, I have a couple I will sell. Neither one has many hours on it because I spent more time messing with them than driving the car. The only down-side is that it appears to be a little taller and there are some air cleaner clearance issues but they are much easier to deal with than taking those darn float bowls off, etc., etc.

[v-mad]

Thanks for your comments. One thing I noticed, is that the Holley was much heavier (6kg) than the Autolite carb (2kg). Can anyone tell me what is the approx. weight of the Edelbrocks?

Mine is now working OK, better since I adjusted the float levels down a bit, but still a bit on the rich side. My fuel pressure is 8.5 which is a bit too high, so I may fit a regulator to see if that improves things.

[Paul & Alexander Breuhan]

quote V Mad:

My fuel pressure is 8.5 which is a bit too high.

8.5" is too high… I would first set the pressure to 6" or 7", then I would recheck the floats and get that straight first. The fuel level should be just below the site holes.

Also I would gentle bottom out the idle mixture screws then turn them back out 1-1/2 turns to start. You also need to make sure not too much of the idle transfer slots are exposed, if they are then the idle mixture screws are useless….so make sure the throttle blades are not open too far.

If you are playing around with the throttle linkage adjustment (attached to the gas pedal) make sure the accelerator pump is properly adjusted. Everything all works together so the more screws you are turning the more chances you have of goofing things up.

I have a 570 cfm Holley Street Avenger on a 289 and it works just fine. When I bought the car is had a 650 DP Holley and wouldn’t run for more than 2 or 3 minutes without fouling the plugs and dying…so it ended up on ebay.

Paul

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