Guest alfredfenech Posted December 28, 2011 Share Posted December 28, 2011 Hi Guys new to the club and not trying to find my way around. My Mk4 cabby finds it hard to start even on hot summer days. I am sure that the automatic choke is not working. I want to get a replacement carb or if possible I would like to fit a manual choke system. Not sure if this is possible. The carb is a Weber twin choke downdraft with the big oval air filter. I have tried on the net to look for a replacement recon carb but no success. Any help would be appreciated. Quote Link to comment Share on other sites More sharing options...
Guest shaun Posted December 28, 2011 Share Posted December 28, 2011 should be able to fit manual choke to a Webber carb... but check the gasket under the carb for split's and inlet manifold gasket not sucking in air... may find fuel pump could be weak Quote Link to comment Share on other sites More sharing options...
iansoutham Posted February 15, 2012 Share Posted February 15, 2012 These carbs are quite hard to get hold of, but were also used on XR2 models. Have you checked the CO on idle using a proper gas analyser? I have one of these with the Webber carb fitted and I run the CO around 1.8-2.0%. As said, the baseplate gasket can perish with age. Spray the area with WD40 or a water sprayer when the engine is running and see if the revs change automatically. If they do, then you have an air leak. If not, you need to check elsewhere. Has the car sat for a long period of time? If so, are all the jets in the carb clean and not gummed up with waxed fuel remains? You should have a water-based choke system on your carb. Mark the outer choke casing so that it can be put back in the same place and remove the unit. Gently heat the choke unit externally and see if the bi-metallic strip inside moves. If it does not, or if it does not move the lever enough in comparison to the strip, then you may need a replacement choke unit. These can be found and are not as hard to get as you may think. If it does move and moves freely, then replace the choke unit and move it a few mm to one way of the mark and try it the next day. See if it starts better or worse. If it is better, move it a little more and try again. Do this until you either get a good starting point, or the quality gets worse. If it is worse straight away, move it the same amount to the other side of the mark and repeat the above. Try this again once warm, and at other times, for example, night time, wet evening, etc... to cover most eventualities. You may find that once the weather changes, you need to slightly alter the adjustment to compensate. Quote Link to comment Share on other sites More sharing options...
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