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carb conundrum

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carb conundrum

Hi all!
I have a '87 cabby which has recently been converted from the injection system to twin webbers. Its running lumpy and apparently needs fettling! Does anyone know of anywhere in Doncaster, South Yorkshire, or surrounding area that would be able to sort this for me? The cars been off road for almost 7 years now and I just want it running again but Ive been advised that it needs specialist equipment to set the carbs up properly? Any advice graciously received!
Thanks all!

83 Helios Blue shell/G60 build
83 1.8Gti Tintop doner car - SCRAPPED!
87 1.8GTi Quartet Cabby now on webbers all in red,daily driver
'90 Caddy Pickup
'83 1.5 Golf bare shell rebuild,knicked by pikeys for scrap

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To set up your carbs you will need to first balance them, barrel to barrel on each carb then carb to carb. Once they are balanced you can then adjust the mixture screws to run richer or leaner.

To balance … You will need to check the carb linkage to make sure both carbs throttles sit closed on idle and operate in syncronization. This should be a screw adjustment between the carbs. Make sure you can achieve full throttle on both carbs too.
Then use a mercury level 'monometer' or air flow meter to measure the air flow pulling into the trumpets- they should all be the same with the exception of the cylinder that has a vacuum takeoff from the inlet manifold for the brake servo and ecu. Warm the engine to operating temp. Unscrew the vacuum takeoffs on the carb and attach the monometer pipes to each of the 4 brass nipples. Screw all the adjustment screws fully in and start working the screws outwards until they are all pulling the same ammount of air on the manometer. Apply throttle and watch the levels on the monometer rise together or not. Then your balanced! If you don't have a air flow meter / monometer then some people use a garden hose. Put the hose in your ear and other end in the trumpet, listen to the pulse and balance them like that.

You can download a .pdf diagram of which adjustment screws are which from the weber / dellorto website.

Adjusting the mixture is then easy. If it doesn't want to run at all, try unscrewing the mixture screws out 7 full turns out from the fully closed position as a base level setting to start from. Then you unscrew each 1/4 a turn at a time listening for the engine to idle faster, keep unscrewing until the engine stops increasing speed. Do this for each barrel. As the engine starts running faster, trim it down with the idle adjustment screw. Then when no more unscrewing (richening) affects the speed of the engine, start screwing in (1/4 at a time) on each barrel until the engine starts to stumble and run slow, at this point unscrew by 1/2 turn and that should be the sweet spot. 1/2 a turn in either direction should make the engine stumble. Then set your idle to desired speed. and you're done!

Mixture screws screw inwards to make lean and outwards to richen. If the carbs spit back through the trumpets that barrel is running lean and will need richening. If the exhaust is popping then you richen also.

Alternatively pay someone £60 an hour to do it.

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:?  Erm………..Thanks! I think! You may as well have typed that backwards for all I understood of it LOL! I think paying someone is the only option to be honest. Sorting the problem is way beyond my capabilities! Now…..to find someone I can trust…………

83 Helios Blue shell/G60 build
83 1.8Gti Tintop doner car - SCRAPPED!
87 1.8GTi Quartet Cabby now on webbers all in red,daily driver
'90 Caddy Pickup
'83 1.5 Golf bare shell rebuild,knicked by pikeys for scrap
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