Over Running

When I bought my 1.8 clipper the pierburg was dead so I decided to fit a brand new webber purchased from VW heritage.

The performance of the car changed dramatically and is so much faster it seems and responsive. Took a few attempts to get the idle speed just right but I haven't played with any other screws.

I have only done about 100 miles since fitting it as she only comes out when its sunny and we havent seen much of that!.

The trouble is when I turn her off she overruns for 1-2 seconds. Its not so bad if I dont just pull up and immediately switch off. If I let her sit for a moment or two and then switch off the over running isnt so bad.

Is this common with conversions to a webber?

Any advice most appreciated!

Could be a few things, fuel cut off is not working on the carb, on mine there is a electical connection to a solenoid, fuel mixture to rich check to colour of the spark plugs after a run out or timing out I think if its to advanced it will cause the engine to run on.

Thank you.

I will check the plugs.

If it is the timing is it possible to adjust without a timing light?

Ive seen a mate adjust the timing on his beetle by just turning the dizzy and listening but surely thats not very accurate! Mine must only be fractionally out?

You can adjust the timing without a timing light just make sure you mark the dissy shaft so you can adjust it back to where it was before you started messing with it if it all goes wrong.
Losen the clamp holding the dissy shaft at the bottom, 13mm spanner needed, clockwise to advance, anti clockwise to retard. Get the car running and advance a little just nip up the clamp as you will need to losen it again to adjust the timing while out for a drive. Keep advancing the timing till you hear the engine start to "pink" underload, 4th gear, 25 to 30 mph and accelerate. Once the engine starts to pink retard the timing a little so it stops pinking under load. You really need a quiet road where you can keep stopping adjusting things then driving again.
Watch out for the fan kicking in when working on the dissy clamp with a spanner and hands as its near to the fan.

Its easier to get the car set up by the book with a timing light but this way the car is set up for how its running, I set the timing on my Mk1 Scirocco by the book using a timing light for the first time when I replaced my point to electric iginition and it was flat and gutless so did the timing this way and drove much better so wished I never borrowed my next door neighbours timing light.

Check your plugs are the correct ones. Using too hot a plug can cause over run and if it's only showing after a carb change it could be due to overly lean running.

Webers are designed to run lean at idle/cruise so couple this with wrong plugs and you'll get overrun.

Incorrect timing could also contribute. You can time by ear but it's not accurate. A gun can be had for about a tenner. Well worth it on older motors that need a tinker.

Can I ask a dumb question?

I am struggling to understand the whole timing issue. The reason I question it is because with the ignition off surely there is no spark from the plugs right? Therefore what difference does the timing make when its not the cause of ignition once the car is turned off/power cut?

Sorry to ask the question but I just want to get a better understanding.

I am running the recommended plugs as per the haynes manual and as supplied by vw heritage as per my engine spec.

So does that just leave hot carbon build up causing my engine to run on from the over fueling of my carb?

Is over running harming my engine?

Overly advanced timing can cause the plug tips to overheat and glow which can cause the fuel/air mixture to ignite much the same as carbon deposits.