Hope this is the right forum? Thought I'd ask the following before messing with the current settings.
New to me '87 351 with Holly 4 barrel carb. PO had shop rebuild carb + electric choke added.
Holley spec on front float bowl;E5YE-9510ZB List 50264-1 0787

Engine starts instantly & runs excellent after a couple miles warmup; without warmup the engine dies first couple times gas applied.
"Instant start" say's butterfly likely adjusted correct or close (~ 1/16th" between throat and butterfly?
Next guess is mixture screws need fine tuning; from tach; high idle both sides + 1/8th turn?

I'd like to disable the 2ndairies unless I need the power but no mechanical linkage between butterflies. How do I do this?

thanks
steve m

 

Well, from experiance here we go, when i bought my truck (87 f-150 351w) it had the secondaries turned off, they did it buy not letting fuel into the rear bowl, ( i think thats the secondaries, i could be wrong) it SUCKED, no pep no power, would idle like crap, and the gas millage, wasnt any better, so first things first dont do that.

Many times i find i need to let my truck warmup a bit before you can dirve it when its very cold out, but im not sure if its normal, i Blame it on the fact i think my carb needs to be rebuilt.

Other than that, I fing the "80-86" forum much more helpfull on carbs, In 87 the f-150 with the 351 was the only carborated truck, and only for one year, so theres not alot of them. and to be honist with you, You and i are the only ones ive seen on here with them, maby a few more but defidently post this same thread in the 80-86 and see what you get, thats where all my carb answeres have come from ing the past.

 

hmmmmmm ...... thanks for the insight. I'll post on the other board and see what I get.
Last 4bbl I had had mechanical linkage and it was easy going back and forth; just took a couple minutes. Maybe you're right and I'll leave it alone; didn't buy the truck for outstanding fuel economy to begin with.

Just seem's it should be ready to go when started tho so not sure about the cold running. PO gave me the shop receipt for the carb rebuild (for the 1 year warranty if it's transferable?) and maybe I'll talk to them. Receipt show's it as a buyout so no idea who actually rebuilt the carb.

Your truck have the duel (hi/ low) trans? Mine has badging for it on the box between the rear wheels and bumer and a electric on/off switch on the gear selector.
It was a factory option according to the owners manual I got with the truck.... a "overdrive/granny gear" on demand setup that at the moment doesn't work and needs repair ...... ford dealer tranny guy'd not heard of it or seen one .... another project

Thanks again

 

ive never heard of it, but clearly it was an option, i dont have it, My trucks got a C-6, but its also 4X4. but whatever it is it sounds pretty cool.

 

we'll see once I get the switch and transfer system working ......one of the few things on the truck that doesn't work, Maybe it has to do with being the xlt lariate .don't know. Also plan to put a sunroof in it as it's the extended cab and should have room for an electric moonroof.

 

<!-- / icon and title --><!-- message -->Thought I'd ask the following before messing with the current settings.

New to me '87 351 with Holly 4 barrel carb. PO had shop rebuild carb + electric choke added.
spec on front float bowl;E5YE-9510ZB List 50264-1 0787

Engine starts instantly & runs excellent after a couple miles warmup; without warmup the engine dies first couple times gas applied.
"Instant start" say's butterfly likely adjusted correct or close (~ 1/16th" between throat and butterfly?
Next guess is mixture screws need fine tuning; from tach; high idle both sides + 1/8th turn?

I'd like to disable the 2ndairies unless I need/want the power but no mechanical linkage between primary & 2ndairy butterflies. How do I do this?

thanks
steve m
<!-- / message -->

 

Moved to proper forum.

 

thanks torque1st, sorry you had to move it .getting to know my way around the forum as a new user

 

Hey steve m your truck carb has almost the same number as mine. Mine will run great, but gas sucks. It always runs rich. Carb had been rebuilt by previous owner last winter. I had it to the shops a few times and no one can find anything wrong with it.
Put stronger 2ndary springs in, it would open at 55 on highway. Also changed metering jets to smaller ones. Still gas mileage sucked. The exhaust is always burning black.
Finally someone said something is wrong internally with the carb and reccomend I get another carb. I'm considering a Edelbrock. Wonder what others from here think. Read lots where guys say to put on an Edelbrock.

BTW here is my carb numbers.
??TE-8510-ZB
LIST-50264-1
1256

What size of carb is it guys. Do you think putting on an Edelbrock will help with gas.
Also the truck does not trailer pull well either. It struggles and I'm having to give more peddle to have it pull a camper trailer. My old truck did nothing like this.

 

You have a 600cfm Holley. It is a 4180 series that uses annular discharge boosters in the primaries. Shutting off the fuel to the rear bowl is no good, these carbs actually have 4 idle circuits. one for each barrel. You must drill out the plugs in the carb base to acccess them. I would try a smaller number powervalve to try to increase economy. It could be opening too soon.