Can't ID my no tag 2100

[doc65]

That's great info Gronk, thanks.  I spent a few hours trying to ID this carb last night & this am.  I want to think that they got it from someone sold as a replacement for a carter based on the linkage.  There is also writing on it in pik/faded red that says PCV/4x4/Dist/Vent etc.  it's got a long throw accel pump, and the taller power valve.  From the engineering stamps I am at a loss to figure what it is though....

[carnuck]

got a pic? There was a Holley replacement for a couple years of the BBD, but I thought only Dodge used them.

[doc65]

I'll get a couple pics, but it's definitely a MC2100(Motorcraft not autolite as Motorcraft is cast in the top cover), just not sure which variety or vintage...

[doc65]

[GRONK]

That is a Motorcraft 2150.  Very late 70's, probably early 80's.  Has a fixed state venturis cluster and a 2 stage accelerator pump.  Would have come on a 302.

[carnuck]

What's the jet size? (pic 1 behind the spring)

[GRONK]

Behind the spring would id the venturis size, not the jet size.  The jets are in the fuel bowl unde the float.

Looks like a 1.08 venturis carb (287 CFM) Perfect size for the 258.

[doc65]

Carnuck,

You mean the venturi size right, the raised cast in number on the side, it's a 1.08?  The jets on the other hand, you  have to be read off the jets themselves down inside the float bowl, they are a 45 & a 46...

Doc

[GRONK]

That's jetted for 5000' elevation if it has  #45 and  #46 jets

[doc65]

Yeah, we "talked" about that a week or two ago, the floor of the Salt Lake valley is about 4500 MSL, but going up into the "hills" could easilly gain you 1000 MSL.  My biggest issue right now is that it just totally falls on it's face when  accelerating at all(VERY light ) just driving it around the block to test.  The PCV is new, the 4x4 labeled port is capped still, and the ported vac goes direct to the dizzy.  Idles pretty nice though...

PS, I just had the thought that once I get the falling on face issue sorted I might jet down one on that 46 to lean it out for emissions sniffer test, then swap back out after... THoughts???

[carnuck]

Errr.... yeah, I meant venturis (where's that smiley guy slapping himself?) With the motor not running, look down the throat and move the throttle to see if you are getting a squirt of fuel right away. If not, the check valve in the Accelerator pump may bad or the nozzle may be clogged. You can fix both by just removing the accelerator pump housing and diaphragm. Replace the rubber valve by wiggling it out and pushing a new one in and spraying GOOD quality carb cleaner (I like 3M) through the opening to see if it squirts in the carb throat.
   At high altitude you may have to advance your timing even more.

[GRONK]

Mke sure your vacuum advance is properly advancing when ported vacuum is applied and that your timing is properly set.  Your timing should be about 12-13deg at 650 RPM when at 4500' elevation.

[doc65]

I think it's about 13* right now, I intend to pull the timing light back out along with a vacume pump and manually apply vac to the vac adv to see whether the adv changes, I was also told that it could be caused by a bad/dried out & ruptured power valve, thoughts? seperately I also don't have the vac choke pull off on this, should I add one? seems that opens the choke plate(some) as soon as the engine is running & making vac.

[carnuck]

Ruptured vacuum advance would do that too

[GRONK]

You can check the vacuum advance bu sucking on the vacuum line to the dist and you can watch it advance.  If you need a new vac advance diaphram it's cheaper to go HEI than to replace the stock dist.

You could have a bad power valve.