Carb Rebuild '88 2001

Got started on the carb rebuild this weekend. Researched a bit on this site and elswhere...didn't really find any good photos so here you go.
Of course I have a couple questions.

here is the carb on the bench. i read somewhere to make legs with bolts. i thought it worked really well.


first thing i did was remove the primary bowl. it took a little gentle prying but came off fairly easy. this is what it looks like underneath.


inside of the primary bowl. after the bowls were off, i took out the floats, the needle valve, the plastic "protecter" and then the seat.


secondary bowl off and view of the secondary metering block. the screws are 5/16" "clutch" head...first time i've ever used my clutch head bits.


next i took off the primary metering block...again, with gentle prying. after the metering block was off, i screwed in the air/fuel adjusting screws until they were seated and recorded how many turns so I'll have a good starting point when it's time to reassemble. next out was the power valve. a 2.5 came out and a 2.5 came with the rebuild kit. finally the jets came out.


primary metering block


next the choke and secondary diaphragm assy came off. and finally 8 screws to separate the main body from the base.

now for my questions.

1)do i need to disassemble the base any further before soaking??


2)do i need to remove the accel pump nozzle (one internet guide said i should)?? to do so it looks like a need to take off the overflow tube first and then the choke plate. seems un-necessary and maybe a little risky to take off the overflow tube.

how else can i get to that big phillips head screw??

i was having as issue with hesitation/miss and sometimes it would die while idling in gear.

i will be changing the accel pump but wasn't planning on changing the secondary.

why wouldnt you change the secondary?

Murphy's law - If you don't change it, it will fail later & you have to fix it twice.

If it's your first, open it over an open shoe box.

Great pics

I have also read (on the site of a certain well know ski boat parts supplier) that's it's not typically necessary to replace the secondary diaphragm. The rational is that this diaphragm is never (or shouldn't be) soaked with fuel, so it's less prone to deterioration. That said, probably wouldn't hurt, although they don't come with the kits; separate part.

Another guy on this site had a helluva time with those J-tubes. Wound up breaking them off and then drilling to get the rest out. The book I have makes it look really easy to get out the nozzle... but the pictures where from an automotive application. I guess you could try a screw bit, with a 1/4 inch drive universal joint, extension and ratchet, but you may have trouble getting enough torque.

The kit does come with a new accelerator pump diaphragm, but you keep your nozzle in there anyway. Do you remember if you were getting a good pump shot?

The book I read strongly recommended against further dissembling the throttle body (base as you called it), because the throttle plate screws are such a PITA to get out and then re-stake on re-assembly. But they said not to soak it, because the throttle plate shafts have tiny nylon bushings that could get damaged by the carb cleaner.

[QUOTE=Dreaming] J tubes are easily removed QUOTE]

define easily

i tried...but, not very hard. didn't seem wort the trouble to me. i was able to get the accel pump nozzle out with a rube goldberg extension set up. i also took the secondary diapragm assy apart too...why not. can I get a new one at NAPA or is this a "marine" specific part??
regarding not soaking the throttle body...are there any passages I should try to blow out with carb cleaner?? the butterflies move smoothly so i'm not too worried about it.

nozzle out


nozzle parts


rube goldberg


secondary diaphragm assy disassembled


i noticed this bushing/spacer on the choke butterfly linkage...is it ok to soak?? it doesn't seem to do much and would be a PITA to get out (J tube). also, how long should I soak all this stuff...hour, day, winter??

If you don't mind paying shipping, you can get your secondary diaphram here: http://www.skidim.com/prodinfo.asp?number=HOL135-4
I can't imagine it's marine specific but I'd want to get a real Holley one.

As far as air passages in the main body, the book I have said there are a few, but only a few air passages and restrictions. Other than... the venturis themselves

got some work done over thanksgiving and now starting to put it all back together. I have 2 questions that i'm hoping you guys can help with.

1) Do I need to check/adjust the float level?? if so, what should it be??
2) Regarding the vent baffle (black plastic piece) in the last picture...is it in the correct location/orientation??

soaked all the big parts at my dads place and blew out everything with compressed air


primary metering block clean


fuel/air screws and new cork gaskets


these are all the parts that came in the rebuild kit from DIM. honestly some of the parts don't appear to be as high quality as the old parts.


primary metering block rebuilt


i couldn't find a new secondary diaphragm locally and ended up ordering a new one from DIM. old is on the left.


secondary and choke back on


secondary metering block rebuilt. 2 gaskets came in the kit that could have gone between the secondary metering block and the secondary metering block plate...i used the one that looked like the old one...second time (and maybe last) i've used my "clutch" head bit...


is the vent baffle in the correct orientation??

Ok...here comes my OCD kicking in.

When you need to take pictures of something very close up, zoom all the way OUT and look for this logo on your camera:



That's what is called "macro mode". It's a fancy term for 'super up close focusing'.

Here are a few shots I took with macro mode:



Thanks for the informative 'how-to' though. Very informative.

P71_CrownVic wrote: Ok...here comes my OCD kicking in. When you need to take pictures of something very close up, zoom all the way OUT and look for this logo on your camera:

i'm familiar with macro mode...the fuel/air screw and accelerator pump nozzle photos above were taken with macro mode.

Thanks for the details Nick. Subscribed! I'm sure I'll need to refer to this in the future.

i've been searching a bit regarding float level and found a variety of suggestions from "level with the top of the bowl" to 7/32" from the toe for the primary side and 5/16" for the secondary side...and even more info on this old cc fan thread...now i'm thinking to just leave them alone

MI-nick wrote: behindpropeller wrote: Take it to your auto parts store and have them boil it before re-assembling. what???

Blowing it out with air will not remove built up varnish.

Tim

TRBenj wrote: watrski wrote: MI-nick wrote: behindpropeller wrote: Take it to your auto parts store and have them boil it before re-assembling. what??? Blowing it out with air will not remove built up varnish. Tim Thats why he's soaking it (and then blowing it out with compressed air, presumably). Ive never heard of "boiling" a carb... it sounds like a fancy kind of soaking? Do most auto parts stores have this capability?

it was soaked, then i sprayed carb cleaner in the passages, then blew out with compressed air.