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> Carb Setup - Opinions Please, Dual or Single
vin man
post Jul 4 2018, 11:35 AM
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I have a new motor in my 914 - 2056 based on the 1.8 core. I had dual weber 40 IDF on the original 1.7 when I got the car and I've been trying to get the motor running but one of the webers is bad.

I have a few options.

Find a VW expert, have him/her rebuild the webers and get the car running right.

Go with new webers keeping the dual carb setup

Look for used dellortos and new linkage to keep the dual carb setup.

Go to single carb setup.

What are the benefits/drawbacks of the single carb? What I can think of:
1- I have to find a new intake setup.
2- Single carb is simpler
3- Less CFM with the single carb so won't be as much power.

Would appreciate any input. Thanks.
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Rand
post Jul 4 2018, 11:45 AM
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Don't go single carb. The intake runners are too long for that to work efficiently. I think you'll find this unanimous on 914s (or any flat engine that would require long intake runners).
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barefoot
post Jul 4 2018, 01:44 PM
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I've just been thru a similar carb tuning issue with dual Dell40 DRLA's. One of mine had poor idle air flow balance between barrels and could not get it to run, lots of popping & backfire. Finally bought another DRLA 40 and that as much better balanced, then tuning was fairly easy.

Get yourself another Webber, or have somebody who knows those things rebuild & balance it.
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xperu
post Jul 4 2018, 01:51 PM
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Duel carbs, also make sure they are not (Made In China). Look at your cam set up to better support your carbs. Mike Kelly
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Dave_Darling
post Jul 4 2018, 01:57 PM
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Never singles on our cars. Never.

--DD
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vin man
post Jul 4 2018, 03:49 PM
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one of the webers is great. the other is wrong. I've had it apart multiple times, soaked overnight in the carb cleaner, blown out every orifice. I can't find anything wrong with it but no fuel is flowing.

I'm game to go with another setup. Dual dellortos would be nice. But the least expensive option would probably be to have a Weber expert fix the one I have.
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cgnj
post Jul 4 2018, 03:57 PM
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No gas in the carb at all? Check float adjustment and check valve.
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bbrock
post Jul 4 2018, 03:59 PM
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Many years ago I ran a single carb on a 1.7 liter 914 and also on a bus. Both SUCKED. Never again.
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vin man
post Jul 4 2018, 04:11 PM
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QUOTE(cgnj @ Jul 4 2018, 02:57 PM) *

No gas in the carb at all? Check float adjustment and check valve.


Float adjustment good. Where is the check valve? Do you mean the valve that is attached to the float? That is good too. I put a new one in when I put the carb kit in.
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nditiz1
post Jul 4 2018, 04:18 PM
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Check valve is under the top plate. It is operated via the float. What you should do.

Buy an all new set of dual 40 idf from a reputable company.

Pick up Bob tomlisons Weber carb book.

Buy good linkage CSP or tangerine.

Install carbs.

Start the tuning process.

Can you work with used carbs, sure if you know what new carbs should act like. With new ones you know the shafts are not worn and they haven't been messed with.

You can sell the old ones or eventually fix the bad one and keep them.
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michael7810
post Jul 4 2018, 04:51 PM
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QUOTE(vin man @ Jul 4 2018, 02:49 PM) *

one of the webers is great. the other is wrong. I've had it apart multiple times, soaked overnight in the carb cleaner, blown out every orifice. I can't find anything wrong with it but no fuel is flowing.

I'm game to go with another setup. Dual dellortos would be nice. But the least expensive option would probably be to have a Weber expert fix the one I have.

Are the accel pumps squirting? Are you sure the engine is OK? Intake leak, valve adjustment, idle jets clogged. Did you put a snail on each side to check airflow balance? I have a couple books on Webers that you can borrow. PM if interested. I’m in S Scottsdale
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vin man
post Jul 4 2018, 04:55 PM
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QUOTE(michael7810 @ Jul 4 2018, 03:51 PM) *

QUOTE(vin man @ Jul 4 2018, 02:49 PM) *

one of the webers is great. the other is wrong. I've had it apart multiple times, soaked overnight in the carb cleaner, blown out every orifice. I can't find anything wrong with it but no fuel is flowing.

I'm game to go with another setup. Dual dellortos would be nice. But the least expensive option would probably be to have a Weber expert fix the one I have.

Are the accel pumps squirting? Are you sure the engine is OK? Intake leak, valve adjustment, idle jets clogged. Did you put a snail on each side to check airflow balance? I have a couple books on Webers that you can borrow. PM if interested. I’m in S Scottsdale

Accel pumps are squirting.
Engine is new. I've got compression on all cylinders
Timing is right
Snail balanced

I may take you up on the weber books. What are the titles?
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worn
post Jul 4 2018, 06:57 PM
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QUOTE(michael7810 @ Jul 4 2018, 02:51 PM) *
e? I have a couple books on Webers that you can borrow. PM if interested. I’m in S Scottsdale

Don’t see how you can make it work without knowing how it outta work, o... (IMG:style_emoticons/default/agree.gif)
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rhodyguy
post Jul 4 2018, 07:31 PM
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Try Blackline Racing in Murray Utah. You provide the engine specs and they set your carbs up accordingly. You're probably going to wind up switching to 32mm venturis. Not exactly cheap but they are good to go out of the box. Plan on a new linkage. Buy a copy of Thomlinson's WEBER manual from CB performance. If you don't currently use one get a rotary self-regulated fuel pump.
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vin man
post Jul 4 2018, 07:38 PM
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QUOTE(worn @ Jul 4 2018, 05:57 PM) *

QUOTE(michael7810 @ Jul 4 2018, 02:51 PM) *
e? I have a couple books on Webers that you can borrow. PM if interested. I’m in S Scottsdale

Don’t see how you can make it work without knowing how it outta work, o... (IMG:style_emoticons/default/agree.gif)


I'm wondering if I missed something in the rebuild (obviously I missed something). I'd like to fix what I have now to save time and $. However, I'm not going to shortcut this after all the time and $ I've put into the rest of the build.

Something is preventing the fuel from flowing. Either the float (which I checked and is working), or an air flow issue. I'm suspecting the latter. Either a passage is plugged or there is an opening causing an air leak. I blew compressed air through all the openings so I'm more inclined to believe I have a missing plug or a crack in the casting someplace.
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rhodyguy
post Jul 4 2018, 07:51 PM
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Chimp Sanctuary NW. Check it out.
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No fuel is being delivered to the carb?
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vin man
post Jul 4 2018, 08:40 PM
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QUOTE(rhodyguy @ Jul 4 2018, 06:51 PM) *

No fuel is being delivered to the carb?


Fuel is getting to the carb and the float bowl.
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michael7810
post Jul 4 2018, 09:41 PM
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QUOTE(vin man @ Jul 4 2018, 03:55 PM) *

QUOTE(michael7810 @ Jul 4 2018, 03:51 PM) *

QUOTE(vin man @ Jul 4 2018, 02:49 PM) *

one of the webers is great. the other is wrong. I've had it apart multiple times, soaked overnight in the carb cleaner, blown out every orifice. I can't find anything wrong with it but no fuel is flowing.

I'm game to go with another setup. Dual dellortos would be nice. But the least expensive option would probably be to have a Weber expert fix the one I have.

Are the accel pumps squirting? Are you sure the engine is OK? Intake leak, valve adjustment, idle jets clogged. Did you put a snail on each side to check airflow balance? I have a couple books on Webers that you can borrow. PM if interested. I’m in S Scottsdale

Accel pumps are squirting.
Engine is new. I've got compression on all cylinders
Timing is right
Snail balanced

I may take you up on the weber books. What are the titles?

I have Bob Tomlison’s Weber Tech Manual and Haynes Weber Workshop Manual. I also have Mr Bubbleheads Weber Carb Tuning Instructions. LMK, I’m leaving town tomorrow and will be home Sunday.
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