Holley adjustments

[Julian West]

Am running a standard Marine spec 302. The Holley has some kind of electric choke fitted & the engine is running quite rich.

Anyone got any info on setting up this carb?

Previously on a Weber DGAS I removed the wole hoke assembly, inc the vacuum operated choke butterfly's & was a great improvement... would this be advisable on my holley?

 

[Guest]

My guess is yes dump the whole choke assembly and run without it. Alternatively treat yourself to a replacement holley. Normally go for a 600 or 650 double pumper or 750 vacumm secondary. Biggest airfilter you can get in is also best.
Malcolm

 

Hi Julian

If you remove the electric choke the butterfly must be locked in the open position or removed. You must do this because the vacume might pull it shut from time to time.

Chris

[ March 01, 2002: Message edited by: Chris Melia ]

 

[Julian West]

Malcolm, Chris,

Thanks for yur advice. I will install the choke assembly in the dustbin & see if it makes any improvement!

 

[Mark Clapp]

Julian, you probably already have, but also check the jet size. Some install large i.d. jets which dump too much gas and also cause overheating. If the choke is opening fully, when warm, then the rich mixture is due to other areas.

 

Julian, also check the power valve to make sure is is not opening at idle and enriching the mixture. Take a good 'ol vacuum gauge and read manifold vacuum at idle. Subtract 2 to 3 and that should be close to the number you will see stamped into the outer diameter of the power valve. Its purpose is enrichment at closer to full throttle conditions, when vacuum drops and fuel demand is high. The Holley is a good carb, but d not believe all you're told about running well "right out of the box". Roger

 

[Guest]

Youre choke must be out of adjustment and not opening correctly for some reason. Taken it off was the wrong way to fix the problem. I hope you dont need it if you have real cold weather, now you will have to warm the engine up at a fast idle before you can drive your car. Cars without chokes will stall when cold unless the carb is running on the rich side to begin with. You never did say if this was a used carb or new carb. What is the model number ?.

 

[Julian West]

Hi Malcom,

I'm not sure what type of Holley it is.. where would I find the model number?

The car just about idles when cold, but is fiune when warmed up, which only takes a few minutes.

 

[Guest]

Hi Julian
Follow up what Malcolm King and the others suggest to make sure that everything is really ok. However before you look at the main jets inside the carb, make sure you have spare gaskets to hand to rebuild it with. It is very unlikely to have the reusable ones on this car. If it is fine when warmed up then the chances are life will be okay. I personally have never run a choke on a Holley in 18 years, without issues. Maybe it doesn't get cold enough here? However as Malcolm says you will now need to warm up the engine before you head out. Unless you have exhaust gas analysis gear to hand or cut the engine when on a fast run to check the plugs, the only other indicator is the colour of the exhausts. If they go black in the tail pipes then you are still running rich. For setting the idle jets I have always turned the screws in until they just pinch tight and then loosen them by 1.5 turns. This has worked for me but I don't know if this is standard. When you come up I can show you how to check and/or set the fuel float levels. I would struggle to write it down even though it is very easy to do!
However still consider junking this carb and getting a better Holley. A lot of owners did in the days when your car was first made to gain a performance improvement. The 750 vacuum secondary was a very popular choice. The engines GTD sold back then were marine spec engines and not spec'ed for a 40 ie crate engines. After a while the factory offered a carb upgrade option.
Now before anyone jumps on me for saying use a 750 cfm carb, which is I think bigger than the formula for carb sizes suggests is the correct size to use with a 302 in standard tune, a story went round years ago that there was a test done on a rolling road (I think on James Shaw's car) when it was set up with jets etc to get the best results. However it then ran lean on track testing. What was discovered and having changed to 2 sizes of jet larger was that the air intakes and rear deck configuration was acting as a pressurised plenum chamber forcing a bit more air through the carb. Something that would not show up on a static test bed of any description. If this was actually true would be interesting to know but the people involved back then are long gone into new pastures. Maybe Andrew can monitor his car now he has static tested it, if the same principle applies to a webber set up over a holley set up.
Malcolm

 

[Guest]

Julian,
The model number should be on the front of the horn, thats where the choke butterfly is, not far from the gas inlet on the right side. It should read like this
list 1850-3
2390.
Dont trow your choke parts away, did you have the choke wired one side to earth, and the other side to ignition switch source? If you put 12 volts to the choke housing the bi-metal spring should move slowly as it gets hot. The trick is to caibrate it to close and open the choke. This is best done when engine is cold, you turn the housing to the left and right and the butterfly should open and close. I have an old address where you can get a manual for your carb, you need the model number.
Holley replacement parts division
Technical service dept
601 space park north
South cartwright st
Goodlettsville,TN 37072.

 

[Guest]

Julian,
Heres another way to learn about holley carbs. Go to www.google.com when the search comes up enter holley carb service. Thers a lot of information on the web about holley carbs.
For an engine the size of a 302 for street use, I like the holley 1850 electric choke. I believe this carb is 600 cfm, vacuum secondary and is good to 6000 rpm. This is my opinion from past experience with american four barrels. The ford mustang 289 used a 600 cfm for some of their high performance engines. If you start changing jets etc, you will need the reusable gaskets that are available.

 

[Guest]

I would never take the electric choke of this carb, these chokes work very well. Over the years I have seen carbs that were destroyed by people who do not understand how they work. First does the choke fully open when engine comes up to its correct tempiture. If it opens fully this is not causing the carb to run rich, you could have high float levels, leaking seats and other problems. First you need a good holley manual, which will take you through the steps to set this carb up and repair if it needs it. This is a simple carb to work on, however it is better to have a manual for all the adjustments. I wish I could be of more help to you, the problem your having could be due to a number of things. Dont be guessing, find the problem, its not that difficult. My son had one of these carbs model 1850 electric choke, he had it all out of adjustment. I took it, made the correct adjustments, float level, fast idle, air mixture, accellerator pump, checked power valve, and choke settings, now this carb runs great. The factory put that choke on for a reason and if working right will fall off a little at a time as the engine warms up. I think the fast idle is about 1500 rpms.

 

[Julian West]

Since earlier posts I've removed the choke butterflies altogether & the car runs *much* better! It now pulls cleanly & doesn't hesitate at all.

A great result & many thanks to all for your advice.

Have done 20 miles in it today!!!