Chinese 34 ADF Swap Help Needed

[btoran]

awesome. thanks. can concentrate on getting the new one to work now instead of testing the old one.

[btoran]

on to jetting the carb. this is something i've never done before, but would love to learn. from brad, these are the Stock 34 ADF jetting settings:

Idle 47/90
Main 120/140
Air 145/180
Emulsion f11/f75

unfortunately, i have no idea what any of that means......yet.

i've seen exploded diagrams of the 32/34 adf, but i don't know how to go about actually changing the current stuff (jets? seats? needles? what the heck do i actually need?) from the old to the new. do i need to open the carb, for instance? so i went to youtube, figuring there had to be a "jetting weber carb for dummies" video, but mostly i found people jetting motorcycle carbs.

so, what's a good source for the above parts and do i need others (like other sizes, internal gaskets, etc). is there a good "how to" for dummies (video or article) floating around? if not, can someone tell me and how the heck i get the new parts into the carb (and where)?

as always, thanks.

[aj81spider]

A couple of sources for jets:

http://www.redlineweber.com/

http://www.weberjets.com/

http://www.webercarbsdirect.com/

For someone who knows nothing about carburetors (like me) I highly recommend:

http://www.amazon.com/Weber-Carburetors ... carburetor

If you want to change more than the jets you're talking about a rebuild, and should buy a rebuild kit. That involves taking the carb off the car and tearing it down, cleaning it, replacing gaskets, etc and reassembling. Should you do that take lots of pictures.

Otherwise you should be able to use the exploded diagrams to see where the jets are. I'm not familiar with the ADF, but on my DMSA the idle jets are behind screws on the front and back of the carb and can be removed without touching anything else. The main jets are in the fuel bowl and require removing the top (it would be good to have a rebuild kit if you do that in case you tear the gasket between the top and bottom of the carb. The air jets also require removing the top and are on the top of the base under the cover.

I knew nothing, got the book, learned the principles, then Googled a bunch of exploded diagrams and have rebuilt two DMSAs since then. It's not that hard - you just need to take a picture of every single screw, rod, and lever you remove so you can get it back together again. Taking all those pictures is a pain, but saved me when it came time to reassemble.

[btoran]

First a great big THANK YOU to everyone that has helped with this so far. Although not completely finished, i'm almost there.

An update......

I originally ordered one of the chinese version 34 adf's but it came with one of the cold water choke barbs broken in transit, so the company sent me another carb, which had the fuel return line broken during transit. they don't pack them very well. so i did a little part swapping and came up with what i thought was a good carb. the second 34 adf has now become my "parts carb". however, i was still experiencing 3 problems.

the first was a vacuum leak at the base of the carb that i couldn't fix despite trying every type of gasket (pre-made, make-it-yourself, etc). finally, i put my old 32 adf back on and the vacuum leak was gone. so i went back to my new "parts carb" and used that base and voila, the leak is gone. so the base of one of the new 34 adf carbs was bad, but because i had an extra base, which was good, the problem was solved. score one for the good guys.

the second problem was that the idle mixture screw didn't seem to have any effect on tuning the carb. i tried the one from my new parts carb and got the same result. brad suggested the jets in the new carbs (which aren't marked) may be way off and he suggested i order jets, etc that should be "standard" for the 34 adf and my 1800 engine. i've done that, but in the mean time, Frank from Autoricambi made a simple suggestion i had overlooked....try the primary jets from my old 32 adf. although they may not be perfect for the 34 adf, they were working fairly well in the 32 adf (before i started the whole carb swap). so i swapped the primary jets from the old 32 adf to the new 34 adf and i'm finally able to tune the carb. it's not perfect, so i'll install the standard jets, etc when i receive them, but for now, it's running, and running STRONG. score another one for the good guys.

the third problem is popping and it's the only problem i have not yet solved. when the car is sitting and idling, i get an occasion burble from the muffler. this also occurred with the old 32 adf. then, when i shift up into second gear (and sometimes into 3rd gear) i get 2 or 3 short pops that i hear coming from under the car toward the back, but not at the muffler. this was also happening with the old 32 adf. in addition to this, i now get some fairly ugly popping on deceleration when i lift my foot from the accelerator. it seems worse going down hills (i'm not sure why). the sound is coming from the same location as the upshift popping (under the car toward the rear but not at the muffler). one difference between before and after the switch is that i de-smogged, so that could be contributing. i checked my exhaust gear (where the popping sound comes from) and found lots of rust on the section of pipe that goes to the center muffler as well as on the central muffler (or cat, i'm not sure which i have). you can see the rust in this picture.



i also found a previous repair made to the muffler itself, as well as more rust from the center thingie (cat or center muffler?) to the muffler, which you can see in this picture.



on to my questions....

1. can exhaust leaks (from rusted pipes, etc) cause popping on acceleration and deceleration and/or the idle burbling sound?
2. what's a good way to check the entire exhaust system (pipes, muffler, etc) for leaks?
3. could de-smogging be the cause of the popping?
4. what is the center thingie on my car? is it a center muffler or a cat?

[bradartigue]

The exhaust can pop, especially with a performance carburetor. No big deal. Popping on decel, rumbling, is kind of characteristic of a carbureted Spider. However it should rumble more than pop.

That rusted center thing is a resonator, and it doesn't look stock. That whole exhaust looks like crap, I'd just buy a new center section and rear section, hangers, and possibly a new cat (or pipe) and replace it. That thing isn't worth diagnosing.

[btoran]

brad - thanks. it looks pretty beat up to me. will replace and see if anything changes.

[lanciahf]

Pops on deceleration usually mean vacuum leaks or the throttle plate is being held open. My friend bought a new EMPI carb and the 2nd barrel was set open from the factory.