Need help/suggestions/opinions, Carbs Options

[drdriddle]

72 914 with 1.7 that I have been restoring for about a year. Bought it with dual Webers and ran very poorly and made it home 30 miles but with Popping and backfiring the whole time. I recently rebuilt the carbs and installed the jet doctor modification to try to solve any debris clogging issue on the air intakes. Verified dwell at 52, timed to 30 at 3300k. No vacuum advance. Pulling 5’s on the snail airflow meter to all carbs. Made sure to disconnect linkage prior to working on idle. Idle adjustment screw all the way in, then advance to touching the plate plus a half turn. Started with air/fuel needles 1 1/2 out on all four and fired well. Minimal monkying to get the carbs relatively synched. Lowest idle I can consistently get without backfiring is around 930rpm, any lower and I get the occasional pop up through an carb throat and it seems to hunt up and down badly. And I brought it up to temp before doing any changes. Any changes I did, I waited a moment for things to settle before changing anything else.

It runs without popping but big hesitation when advancing throttle for just a moment then she goes well. Runs better off idle circuit, but I’ve read at steady pace some idle circuit is still there? Hesitation from steady pace at slow and mid range rpm…but runs well over 4K without any hesitation when getting on throttle hard. Additionally throttle let off gets me a lot of popping out the tailpipe. I did swap the exhaust for a bursch (sp?) and it sounds awesome btw. No more tinny sounding VW motor

So these are 44’s and everything I’ve read is saying these are too big for the motor size. Strongly considering dropping to 40’s but it’s a chunk of money to do that. I do know that the mains and other jets are the standard sizes, I think 11’s for the mains?(been a couple months since I looked at all the numbers, but at the time I verified they were all the normal ones supplied as if I had bought them new).

If I need to drop down, is 40’s acceptable. The air filters and bases, linkage etc will work with 40’s and I don’t want to have to buy all that as well if I don’t need to, but would 36/38’s be a better choice?

Or

Do I get some different jets, and start going that route? I’m at a higher elevation of 3500 feet and feel like different jets may certainly help. But I don’t want to do that if the entire carb (44’s) are too big for the motor and end up chasing my tail of the starting point isn’t correct

What say you all, and thank you for any input.

[Superhawk996]

44’s are too big. Especially for a 1.7L.

Being at 3500 ft makes the situation with an oversized carb even worse.

I would seriously consider going to EFI if at all possible. And I say that as someone that ran carbs over 100,000 miles. You just can’t beat fuel injection for its ability to deal with altitude variation.

There isn’t enough detail in your post to be helpful. You can choke a 44 IDF Venturi down to about 30mm but honestly you should be running 28mm Venturi. The larger throttle butterfly plates on the 44 IDF’s are always going to hinder off idle transitions due to their larger size than 40 IDF’s. You’re going to spend money on smaller Venturi’s and re-jetting and still aren’t going to like the result.

The smaller IDF’s aren’t nearly as common as 40 IDF’s that most of us and the VW Bug & Bus guys use. Not sure how well supported those smaller IDFs are (rebuild kits / Venturi’s / jets). I would do some research before moving to something other than 40 IDFs.