Single port 1300 will be a bugger to tune. Twin port may benefit from small choke twin carbs.
Failing that, the best conversion for the 1300 twin port was a set of cut down 1500 barrels and pistons. In case people suggest I'm wrong, I did that conversion in the very early 70s and it worked a treat.

 

Sorry, I forgot to mention that it is a twinport !!!

I need this car to remain driveable, what happens to the choke if I change the carbs, in the parts catalogue some say they have no choke and some say compatible with electronic choke...

...will a carb upgrade mean I wont be able to get my carstarted on a cold morning???

 

To be honest, it's best to keep 100% stock and keep it well maintained. It will also be very reliable too with no issues at all.

 

To be honest, one of the main reasons I was considering a carb upgrade is because I have a sudden drop in revs between 2nd and 3rd gear, which also appears between 3rd and 4th gear but not quite as severe.

I pull away in first fine, nice and smooth, it changes up to second fine with smooth power delivery across the rev range, but then when I change into 3rd, I get a sudden drop in revs and the car struggles to maintain speed, I have to really rev to keep the car at speed. I have tried changing from 2nd to 3rd in both low and high revs but the problem is still present. A similar thing occurs between 3rd and 4th but no where near as bad and providing you keep the revs high it will maintain a fairly constant speed.

I have only had the car a couple of days and im certainly not used to driving it yet !!!

Does this sound like a carb problem !?!

 

nope, sounds like a dizzy problem. is there a vacuum can attached to the side of your distributor housing? if not, you have the dreaded 009, wooo.... always been pretty crap, unless you're a drag racer.
also, if you have a chrome racy style filter on top of your carb, throw it away and get a stock one, with a warm air pipe going to it.
good luck

 

Is the distributor something that can be adjusted / maintained or should I consider an upgrade / replacement ???

 

what i meant was- a lot of distributors are incorrect for the type of engine. couldn't tell you why, but there's an amazing amount of 009 distributors which have been fitted at some point and they're crap... will defo cause a flat spot, unless you adjust your carb to compensate, which may well make the car overheat... the distributor can be maintained in that the points can be adjusted or replaced, the rotor arm can be replaced, cap can be replaced, and rotating it adjusts the timing... but if you have the wrong distributor, and it's causing a flat spot, the only real way to fix that is to get the right one in your car.
post the number on the side of your distributor up, the carb number (on the left hand side of the float bowl) and the engine number... should be able to tell you if it's the right one or not

 

The ignition timing can be set with a strobed timing light by adjusting the distributor, but the points gap must be checked first.

As Happystamps says, it seems that you have the junk (centrifugal advance only) 009 distributor fitted which is only fit for the bin and should be replaced by the correct vacuum advance distributor for your car's engine.

A pic (or few) of the engine bay will help us to pinpoint any potential problems too.

 

Hi, Thanks for eberyone input !!!

I have had a chance to drive my new car around this weekend. I defenately have a flat spot at low revs particularly between second and third gear although the car starts first time and idles strongly !!! When I apporached ring roads and junctions and put the clutch fully down to slow down, I have found that the engine suddenly drops in revs and cuts out. But it then restarts really easily and I can carry on my journey which is making me nervous, particularly in busy trffic !!!

( as requested ) Hopefully there is now a picture of my engine as it is now below !?!

Ant advice would be greatly appreciated !!! I have now started reading "How to keep your vehicle alive " cover to cover, hopefully soon I will be a fountain of VW knolwege !!!

 

I see a few problems looking at your engine bay pic, which are the following:-

- The vacuum hose from the distributor to the carburettor's left hand vacuum port should consist of the vacuum pipe and two short lengths of rubber hose. The correct vacuum pipe for a beetle is available from Megabug second hand.

- The pancake air filter should be tossed in the bin and replaced with a stock air filter unit (with the vacuum hoses connected in the correct order). I would recommend the later paper based air filter units (from 1971 model year). These are available second hand from Megabug.

- The toothed fan belt should be replaced with a genuine V belt (made by Optibelt). These are available from the VW Classic Parts Center (I will try to find one of the other threads where I had found a UK office for Optibelt), part number 111 903 137 D

- The cheap and nasty GSF fuel hose should be replaced with suitable fuel hose (eg. compliant to SAE J30 R9). Those fuel hoses are available from Volksbolts aka Hairy Yeti on here.

- The purple wires that go to the idle solenoid cut-off valve and the automatic choke should be black (which is the correct colour according to the wiring diagram for your car)

- If you haven't got a fuel filter fitted already (do not be tempted to take the fuel pump apart to clean it's filter), fit a disposable plastic fuel filter next to the fuel tank.

 

Also have a look at a related thread on here, it just reminded me that GSF apparently sell the Optibelt fan belts as well.

http://www.volkszone.co.uk/VZi/showthread.php?t=604644

 

Cool !!!

Thanks for the information !!! Its nice to get a second oppinion !!!

 

Flat spots are usually timing ralated. I'd check the vaccum take off pipe (from the pic it looks like you've got a late servo assisted bay manifold fitted - not a problem at all and will be fine as long as the take off is sealed up ok) and the manifold rubber boots for leaks just in case then if they are ok, get it tuned up first and take it from there

Change the air filter for a stock oil bath one - usually about a tenner 2/h. If it's pulling the vaccum ok the hose distributer (suck on it) vaccum pipe will be fine. Fuel hose wise - if it's looking a bit old replace it for something that says suitable for unleaded on it - available from any car parts shops. i'm not a fan of the braided stuff as you can't see the rubber cracking underneath.