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Mon Nov 10, 2008 8:00 am

1776cc
Single Weber IDF
unknown idle jets
130 mains that were reamed larger
Was an 009, now ACN SVDA w/pertronics

I got my SVDA from John last week & installed it over the weekend. Can anyone offer an opinion of whether the SVDA would tend to lean out the mixture?

I am trying to track down the source of some backfires out of the carb, and the exhaust which was dark (presumably rich) before the install is no longer... at all. I did clean all of the plugs as well, tho.

THis motor was sitting for over a year, and before I did not have this popping, so I am sure it is in need of a cleaning. I did not take a moment to remember the idle jet size, but I did not think they werre 50-55, which I read is what my single 40 IDF should be running.

Does anyone have any ideas why this popping would be happening, or if it is truly just a dirty carb?

I have not taken it out on it's maiden voyage since the restoration. Partly because I want to get it dialed in, and partly because of the neibors POS broken down ford parked in front of the garage!

Mon Nov 10, 2008 8:09 am

I'd contact John and ask him. First off it's his product, AC.net provides superior customer service and John knows a few things about VW engines and his products.

Mon Nov 10, 2008 8:37 am

Glenn wrote: I'd contact John and ask him. First off it's his product, AC.net provides superior customer service and John knows a few things about VW engines and his products.

I just did and have not heard back, but also wanted to hear the consensus from the group?

Mon Nov 10, 2008 9:59 am

KevinAlbrecht wrote: . I did not take a moment to remember the idle jet size, but I did not think they werre 50-55, which I read is what my single 40 IDF should be running.

!
popping back through the carb(backfire) is caused by only a few things.. either too much spark advance, or bad valve or valve adjustment... if you are not hooked into proper ported vacuum you could be experiencing full vacuum advance when you don't want it.. this could cause overly advanced spark and backfire..

Mon Nov 10, 2008 10:17 am

bugninva wrote: KevinAlbrecht wrote: . I did not take a moment to remember the idle jet size, but I did not think they werre 50-55, which I read is what my single 40 IDF should be running.

!
popping back through the carb(backfire) is caused by only a few things.. either too much spark advance, or bad valve or valve adjustment... if you are not hooked into proper ported vacuum you could be experiencing full vacuum advance when you don't want it.. this could cause overly advanced spark and backfire..

Here is where I hooked the vacuum:
http://www.thesamba.com/vw/forum/album_page.php?pic_id=338307

Mon Nov 10, 2008 12:14 pm

Is your firing order correct?

Mon Nov 10, 2008 12:36 pm

Did you time it with the vac pipe attached or removed what is your full advance?

Mon Nov 10, 2008 12:53 pm

krusher wrote: Did you time it with the vac pipe attached or removed what is your full advance?

That is the question! My timing light was flaking out yesterday, so I cannot be confident on it's full advance. I got as far as setting the static advance, to which it ran quite well!

I will need to either diagnose my light, or pick up a new one.

- Thanks

Mon Nov 10, 2008 7:29 pm

The way I always time the SVDA distributor is with the vacuum line disconnected set it to 30-32 degrees full advance. Then reconnect the vacuum line.

IIRC, the SVDA puts the firing order 90 degrees off what the 009 was. Counterclockwise if I remember right, but can't be sure right now.

Mon Nov 10, 2008 7:31 pm

Eaallred wrote: IIRC, the SVDA puts the firing order 90 degrees off what the 009 was. Counterclockwise if I remember right, but can't be sure right now.

Mon Nov 10, 2008 7:46 pm

Eaallred wrote: The way I always time the SVDA distributor is with the vacuum line disconnected set it to 30-32 degrees full advance. Then reconnect the vacuum line.

IIRC, the SVDA puts the firing order 90 degrees off what the 009 was. Counterclockwise if I remember right, but can't be sure right now.

Yeah, I am sure it is installed correctly, otherwise I would notice how it was running. Doesn't pop every time, like every thrid engine rev.

Like I said in my original post, this motor had been sitting for prolly over a year, out of the car, and then another year in the car where the gasoline evaporated out of the carb. I am sure that left some residue. The reason I had asked if the SVDA would make an engine run leaner than an 009, is my exhaust color. Went from black with the 009 to not black with the SVDA. I did also clean the plugs, so that would allow for a more complete burn as well.

I timed it statically according to John's instructions, but my light seems to have a mind of it's own wheather it wants to flash, so I did not get to check the timing advance.

John has let me know he needs to know what are all of my jets before he can offer an opinion. That will have to wait till next weekend before I can get back to the shop...

Anyway, I threw some carb cleaner in the tank, as well as sprayed down the throats & (emulsion?) tubes.

Tue Nov 11, 2008 9:21 am

Now I am questioning myself. I connected the inductive pickup of my timing light to the No 1 wire, and was not getting a copnsistent strobe. is it possible that the reason I was not getting a consistent strobe was that the No 1 Cyclinder was not firing? It is a new SVDA.

Sorry for the Noob question, but it has just been a year (or two!) since I have worked on engines.

I cannot get to my bus until next weekend, so I would really like to get a checklist of things I need to check. Here is what I have:

1. Check the jetting of Mains: Fuel (I am pretty dure these are using 130 mains that have been reamed out by my mechanic in Florida when the motor was built.)
2. Check the Mains: Air
3. Check the Idle: Fuel
4. Verify the No 1 Cylinder is actually where I think it is.

Anyone else have something to offer so that I have a complete checklist?

- Thanks!

Tue Nov 11, 2008 11:56 am

~Bump~

Where is the best place to get some jet sets?

I found this site:
http://www.carburetion.com/Weber/weberpartsjetkits.asp

I also looked at ACN.

Any input, or suggestions?

Thu Nov 20, 2008 9:19 am

KevinAlbrecht wrote: ~Bump~

I found this site:
http://www.carburetion.com/Weber/weberpartsjetkits.asp

Any input, or suggestions?

I am really scraping for some advice, here.. I ordered an adle jet and main jet kit, and installed jetting accroding to Thomlinson's book. I still get a pop if I really dump the throttle linkage, but not if I use a more conservative acceleration. I do not get the pop every time, either?

The distributor is as Glenn pictured it. I am timing it (with light) to 28-30 degrees total advance.

I'll be down there this weekend. Can anyone offer some things to try?

Thu Nov 20, 2008 10:05 am

check your SPAM folder. You would be shocked at how many guys have our e-mails wind up there, or who have invalid e-mail addresses (my replies bounce as undeliverable).

John
Aircooled.Net Inc.

KevinAlbrecht wrote: Glenn wrote: I'd contact John and ask him. First off it's his product, AC.net provides superior customer service and John knows a few things about VW engines and his products.

I just did and have not heard back, but also wanted to hear the consensus from the group?

Thu Nov 20, 2008 12:02 pm

[quote="john@aircooled.net"]check your SPAM folder. You would be shocked at how many guys have our e-mails wind up there, or who have invalid e-mail addresses (my replies bounce as undeliverable).

John
Aircooled.Net Inc.
[quote]

Thanks John. I did get your email after I had posted that. I have not had a chance to write down the jetting, and I would not even know what my stock fuel pump puts out. I will get that info this weekend. - Kevin