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Mon Jan 19, 2015 10:26 am

Hi all, I have some questions regarding the setup of my dual Dellortos carburetors (DRLA 40). I have spent the last few years doing a full ground up resto-mod on my 66 Bug and I live in the Seattle / Pacific NW area.

Here is a little backstory: I built the engine myself (first time, with guidance from a local VW machine shop, Northwest Connecting Rod) and did the break-in a little over a year ago. All went fine, but it ran poorly at idle. I bought the carbs used from eBay, but they had been rebuilt by ACE back in 2011 or so (paperwork included). In my in-experience, I just bolted the carbs on and went for it after reading/doing the initial setup procedure in the Dellorto Super Performance book from CB. I moved onto other things with the car and I’m now just getting back to doing the final tuning of the engine. I recently pulled the carbs apart to verify all the jets and float levels. The floats were pretty off (which surprised me coming as rebuilt) and have now adjusted them per the specs in the Super Performance book. Also, I pulled the plugs and it looked like it was running lean.

This is my first time adjusting carbs, so I’ve been a lot of reading here. I’ve looked up similar setups and what others used for jetting for Dellortos and I’ve seen some varying sizes listed for jets. I was using CB linkage, but I wasn’t super happy with it and have now installed the Gene Berg setup. I also have an LM-2 AFR that I am installing to help with tuning.

Engine Specs:

1776cc with 8.5:1 Compression
40x30.5 Heads
Engle 110 Cam
1.5” A1 Performance header and hideaway exhaust (currently with j-tubes)
Berg Linkage
Megajolt Ignition (used a SVDA during break-in)

Here are the current specs on jetting:
Venturis – 34
Idel Jet – 60
Main Air – 180
Main Gas – 140
Emulsion – .2
Accel. Pump – 55

Let me know if I missed anything. Any tips/suggestions on proper jetting for my engine setup would be greatly appreciated!

Mon Jan 19, 2015 10:49 am

take the main jet stacks out and plug the LM2 in and drive around for a while, that will tell you where you need to be with your idles and where the idle jets stop working.

It's surprising how much driving you do on idles

Mon Jan 19, 2015 10:59 am

Ok, sounds good. What about the venturris, from the reading I've done, it sounds like I should be running a 32 or so. Or should I not muck with it and wait until I get my AFR readings?

Mon Jan 19, 2015 11:42 am

Drive with the 34s first.

Mon Jan 19, 2015 2:03 pm

John@Aircooled was very helpful to me when I went through this. http://www.thesamba.com/vw/forum/viewtopic.php?t=504189&postdays=0&postorder=asc&start=0 If you follow his teaching, you'll come out just fine. As you'll see if you read that thread, I would HIGHLY recommend actually measuring the jets you have, unless you know for sure they haven't been "resized" in the past. My "60" idles measured out closer to 80 :shock:

Mon Jan 19, 2015 4:36 pm

Cool, good idea on double checking the jets, they all look like original jets (had the dell stamp on them) but better safe than sorry, plus I always like to buy new tools! I read that thread about AFR tuning a while ago, it's kind of what inspired me to buy the LM-2.

Thanks for all the tips. I'll get buttoned up and try the suggestions then report back.