Leaking carb

[4babycar]

Well, today Betty just shot her first chance to get out with other Fiats tomorrow. I think she may have a complex about her cosmetic imperfections.
Anyway, we were supposed to take her on a drive tomorrow but late this afternoon, I started getting a strong smell of gas from the engine compartment and just happed to see a single drop of fuel as it fell from one of the carbs. As I watched for a another minute, it happened again. Fortunately, the car was off. I will be honest, I know almost nothing about carbs and especially about dual carbs so can anyone help me diagnose the likely problem and how to fix it? It has been wonderful driving a spider again and I don't want to be down and out for very long but I understand the potential consequences of driving/starting with a fuel leak. Below is a picture of where the droplets have been coming from. It appears that the fuel is leaking on the head side of the carb and then following the linkage (?) that is behind the point where the drops come from. I can't see what is on the other side without doing more disassembly so I wanted to ask the experts first. I wasn't sure if this is a similar problem to the other leaking carb post so if this is redundant, I apologize. Thanks!

[So Cal Mark]

looks like you need a new accelerator pump diaphragm

[4babycar]

Ok, that being said, does anyone have a diagram on where/how the webber 40 idf's are assembled so I may know how to go about changing these? This also begs the question, is there anything else that I should do while I am in there and should I do both carbs now, even though the other one seems fine (at this moment)? Finally, I have found several rebuild kits but I have not been able to locate just the diaphragm. Does anyone have a part # or a source for just the accel. diaphragms?

[mdrburchette]

It looks like you got the 13/15 IDFs. I get my acc diaphragms from Pierce Manifolds and always get two even if I only change one. When ordering, make sure they know you have the diaphragm with the little button (the IDF 70s are different). I believe they have a breakdown of the carbs on their website. The diaphragm is easy to replace. Just remove the four little screws from the housing. Be careful not to lose the spring that will surely pop out when removing the housing. Intall your new diaphragm on the housing. The hard part is keeping the diaphragm aligned while getting the spring back in and starting the screws so it doesn't pinch the rubber. An extra set of hands is always welcome for this! If you need more info, I can copy what I have from a Weber Tuning book and mail it to you. Send you address to Spyderlady71@yahoo.com

[4babycar]

Thanks Mark and Denise. Where can I find a model # or such that I can tell exactly what I have. All of the information that I have is based on what the PO has told me so I would like to start identifying and sourcing the proper parts for future items.

[mdrburchette]

In your picture, do you see the little raised oval shaped part of the housing right over the diaphragm cover? Clean that off and you may be able to read the number there. It'll have WEBER 10, 11, 13, or 15 stamped on it.

[4babycar]

No such luck on the stamping on the raised oval area. Is there anywhere else it could be found?

[mdrburchette]

Here's how you can tell if you have the old 13/15 IDFs or the 70 series, newer IDFs. The 70's have an adjustment screw at the acc pump arm. It's that arm that comes from the pump cover and goes under the carb. Yours doesn't look like it has any way to adjust it. Another way you can tell is when you pull the diaphragm out. The 70's has a fixed button on the brass piece in the middle of the rubber. The older models (13/15s) have a little white button that can be pushed in. It's clear as mud as soon as you pull that diaphragm out!

[4babycar]

Man do I hate incompetent/inattentive parts suppliers! I ordered 2 complete rebuild kits (Because Mr. Murphy says if I didn't I would have needed something else too) and the supplier said that the kit contained two accel. diaph. one for the new style and one for the old. I even called to confirm that it would fit. Anyway, the parts arrived today and the kit came with 2 of the old style so I am stuck until I can get it straightened out and get the right ones in. This SUCKS!

Anyway, I think I figured out a little trick to help keep everything together when reassembling everything. It seems that the real trick to this repair to putting the plate (with 4 screws) back in without dropping the screws and still keeping the diaphragm on the screws so it isn't pinched. I found that if I inserted all 4 screws into the plate and placed a rubber band around the perimeter of the 4 screw heads, it provided enough friction that the screws wouldn't fall back out. Once you do this, place the diaph. on the screws, set the spring in place, lightly seat the screws and cut the rubber band. I know, I know..... You want pictures and when I get the right parts I will see what I can do.

[mdrburchette]

Why would a rebuild kit have a part for one series carb and one for another? That doesn't make sense to me!

[4babycar]

I am sorry, I mis-typed. It is labeled a repair kit but it said it included both styles of diaph. and I called to confirm. I don't know why but that is what they said. Anyway, after 12 calls today, to get the customer service person who knows the difference, I should have 2 new ones on the way. Lesson learned, I should have called Pierce. Hopefully, I will have them in time for the weekend, even though it is supposed to be cool.

[Zamise]

Oh man did I ever have nightmare with getting a diaphram for my carb... Calling them incompetent parts suppliers is being soft, I wanted to strangle them and their computer systems. They knew it was wrong after I showed them, yet they refused to fix it, which means folks will just keep getting the wrong kits.

Oops...edit... I see you've already got a hold of Pierce Manifold (800-874-3728)?? I can't remember the name of the dude, it might of Steve not sure, but yeah there is a guy there that will help you out with whatever part you need, he knows these carborators like nobody else I had spoke to about it. If anything you can send it to them and they'll make sure you get a matching one. They are realitively cheap too, I highly recomend them for anything you may need to replace on the carborator, especially the diaphrams. Thanks to the folks here who recomended them to me too, wish I would have went with Pierce first too.

Does your car actually have two carborators, or do folks just refer to a carb with a secondary opening as a dual carb? I'm a bit confused about that and wondered if some cars actually had two carborators on them or not.

Oh, and another trick for holding screws sometimes I use is to get a paper strip and punch the screw through it and hold the strip, then just pull the paper out before you get it really tight. I had my carb out of my car though so it was easy and didn't have much trouble getting any of the screws in it.

Good Luck!

Zam

[mdrburchette]

Pierce are good people when dealing with Webers. The dual carbs are actually two separate carbs:

[4babycar]

I finally got the correct parts on Monday and put them in. It seems to be that you have to get the right person in order to get the right parts. Every time I spoke with the vendor I used they would say 'You really need to talk to Jose' and then they couldn't find him. I was beginning to think this Jose was just a mythical creature that only appears once every 1000 year or so but I did finally get him and he did send out two new diaphragms at no charge, just a week later than I wanted them.

The other trick that I had to use on installing was that I had to place a screw in the second pivot point hole for the diaphragm cam so I wouldn't be pressing on it during install. Once I figured that out it was easy and no leaks!

[Tappy]

damn denise , i always getting jealous seeing your engine bay , and it probably it al works also !!

where did you get those air filters on those idf's ?they look...well yeah ....stunning !!!