Hoping to get input, or suggestions whether i should consider buying a new carb, or rebuild the old.

Purchased 65 truck several years ago with 1965 390ci and a Holley 4 barrel. Currently, excessive dripping from accelerator pump area. Has model # 1850, so assume an old carb. Have never done anything to it other than carb cleaner down throat on occasion. Not sure whether should try and rebuild the carb, or replace. Another option, try and repair the accelerator pump problem. If need to break carb down to repair accelertator pump, then rather try and rebuild the carb. Not sure of cost for rebuild, or how many more to expect with the rebuild. In the long run would it be better to bite the bullet and purchase new carb. Not sure what is involved in rebuild. Consider myself mechanically inclined, but short of patience.

Any suggestions, input would be appreciated.
Thanx,
dave

 

Dave,

The 1850 is a popular general purpose replacement carb. There are thousands of them on the road.

I would rebuild it if I were you. You will be surprised. It is really not a difficult job. My recommendation for you is if you chose to rebuild it, do it with a Holley rebuild kit. Don't use any other brand. There have been to many problems reported with other brands. The kit should run no more than $30.00

Just pay attention to how it comes apart so you can assemble it easyly. The important thing to remember is everything must be clean. Very clean. I soak all of the small parts overnight in a gallon can of carb cleaner. Then use a couple cans of carb cleaner to clean out all of the small holes in the carb's body.

Post again if you need help on setting up the carb.

Good luck,

 

Lee,

Appreciate the information. Need to move on this asap. Will check w/ local auto parts store tomorrow and see if they have Holley rebuild kits. In meantime, went to couple of web sites and obtained 3 Holley rebuild kit part #'s. If unable to obtain local, will speak to online sales person to ensure get correct kit. Most expensive of the 3 is only $20. Does not seem like it cost enough to include all the items. Will get a gallon can of the carb cleaner, disassemble the carb and let set over night. Have couple of aerosol cans that i can use for reassemble. Can't afford to let set too long, incline to believe suffer from short term memory loss.

Thanks again for the input. Will post if run into problem.
dave

 

That kit may NOT include the power valve, especially since they are usually tailored to the application, but they aren't much and I'd definitely replace it while it's apart. Yank it out and see what number it has on it so you can get the same one. Also, I'm glad to see the recommendation of the soaking in the carb cleaner bucket. That stuff is great, but a lot of people don't use it,thinking the spray can stuff is enough, but a good overnight soak will remove all of the varnish/deposits and help insure a satisfying rebuild.

 

Appreciate the info. Will add the power valve to shopping list.

Thanks again,
dave

 

If it runs fine and just drips out of the pump diaphram, you can buy that separately.
Just remove the carb and it can be changed by removing 4 small screws. Very easy.
PS, most kits include a new powervalve. You have a 600cfm manual choke 4160 series Holley. They are good carbs. When getting a kit, if you are going to overhaul it, make sure to use the whole list number. There are a couple of different revisions so newer ones will be like 1850-1 1850-2 or 1850-3. Use a genuine Holley rebuild kit. Make sure that all gasket areas are cleaned good before reassembly. Blow out all passages in the metering block too.
It uses a special tool to remove the metering plate in the rear of the carb. If you don't get one, just leave the rear bowl on. The metering plate must be removed to replace the rear bowl gasket.

Jimmy

Jimmy

 

Really appreciate the info.

Went ahead and purchased the Holley rebuilt kit. LxMan, believe got the updated kit, it had number of additional gaskets, etc., assume to cover other models. Found saving the old gaskets helped w/ determining correct replacement in the assembly. Soaked as many parts as could fit in the gallon can overnight, removing items that could be damaged by the chemical. Blew out all passages and metering blocks. Carb is back together except for the pumb discharge assemble. Almost certain paid close attn. in disassembling, but when i went to install the pump discharge assembly the parts list calls for a 'pump discharge ball weight', goes between the ball and the needle. When i removed only recall the needle and ball came out of the housing. Decided to take a break and review tomorrow. Does not seem correct for the needle to set on the ball. If unable to solve, will assemble as recall it coming apart and see how runs. Meantime, will check and see it can purchase the part or assembly.

Hope to fire it up tomorrow. Input was very helpful. Glad took the advice to rebuild. Little more knowledgeable in making adjustments. Want to thank everyone again.
dave


Thank you all,
dave

 

Aint no ball and needle going down that pump discharge assemby at the same time. Reviewed couple of Chilton's and show only needle. Thats what decided to go with and see how it runs. Have parts person looking into whether there are replacemetn kits. Everything back together, and all the mechanical linkages seems to be working fine. Holding off installation until tomorrow, want to review the adjustment section again before hand.

Thanks again,
dave

 

My experience has been bad with rebuilds whether I've done them myself or had them done for me professionally so I go with new carbs whenever possible. That's just my experience, others have hed good luck with rebuilds.

Stan

 

The ball/thin rod, keeps fuel from siphoning into the venturies after you have pushed the pedal. This would mess up the air/fuel mixture.
At least install the ball from the kit.

 

Thanks LxMan, did install the ball/needle valve. Stan, did have second thoughts about rebuild attempt. Looking at the Holley street avenger as replacement. Although this is first attempt at carb, not first time had to absorb the cost for the attempt to repair a piece of equip. Hope that when i fire up the truck tomorrow, saved $350.

Appreciate the input,
dave

 

Good luck, let us know how it goes.

 

Installed yesterday and started right up. Took for test run, even better, no stalling or hesitation. Just fired up this morning. Will have to get use to a new starting procedure. Use to pump accerlerator like a mad man before truck would start, flooded it this moringing as a result. Started on second attempt. Adjustments probably need some fine tuning. Fuel bowl level may be a little high, need to find flat ground to set. Went by the instructions for setting accelerator pump. Just did not seem right, so did what normally do in these situations, stuck wet finger to the wind and adjusted accordingly. Going to hold off until replace spark wires, noticed slight arcing last night. Replaced all of the other ignition components fairly recently.

As usual, broke out my 65 truck shop manual after the fact. Intend to read throught and see if better explanation on the accelerator pumb adjustment. As for the choke adjustment, used a 5/16th drill, not sure about that. After a rebuild kind of get familiar with carburator terminology.

Will likely be couple weeks of test runs before plan any long trips just yet. Somewhat upset at the end with my nozzle discharge mix-up, but dispite that, i am very please with the outcome.

Really appreciate everyone's input, took your advice and the rebuild was a success.

Thanx again,
dave