- Tue Jul 15, 2014 11:13 am
#3886
I'm sure most of us have had some experience of carburettors in motorbikes and - if you are old enough - cars as well. My least favourite is the Amal range (fitted to all the old Brit bikes I've owned) because their behaviour is crude: they invariably have a slight hesitance or flat-spot as you crack them off idle; and the lack of an accelerator pump means you can either stall the engine by opening them too quickly from idle, or at least get less acceleration than is possible due to their lack of an accelerator pump. On my cars, the best carbs I've ever used in terms of smooth, glitch-free behaviour are definitely the SU constant velocity carbs. They aren't the best in terms of acceleration (because they provide acceleration enrichment by temporarily restricting the air flow), but in all other ways they are a joy to use, with none of the flat spots, non-linearities or other niggling annoyances of traditional designs like the Zenith and Solex. The best for performance were probably the well-known progressive twin-choke Webers. When it comes to motorcycles I was pleased to find a CV carb on my Electra X (dammit, I can't remember the make). As with the SU, I can honestly say the carburation was superb. Obviously it was (deliberately) on the edge of being too weak, but in terms of smooth progression, predictable response and complete freedom from glitches, it was superb. You wouldn't use one if you want the best performance, but for great fuel economy and perfect usability I've never known better. Do any of you guys have a favourite carburettor for your motorcycles?
