The Hotchkiss M201 6 volt jeep was originally fitted with the same Carters carburettor used on the Willys MB and Ford GPW. It is difficult to say exactly when the Solex carburettor was introduced but as a result of the rebuilding programme most M201s, though not all, ended up fitted with the Solex type which is said to be more fuel efficient and is certainly a lot less fiddly to dismantle and reassemble. Over the years I have been asked many times about how you adjust the running mixture on these. The straight answer is that you can't. It has a fixed main jet and the needle screw adjuster at the base of the main body (see above) only adjusts the idling mixture. If you are having issues with fuelling then, in terms of the carburettor, it is a matter of cleaning out, checking float level, manifold gaskets etc. A repair kit is available from most of the usual sources.

If the problem persists then a rich mixture can be caused by fuel dripping into the manifold from the main jet casing which can also cause idling and starting problems as the contents of the float chamber can flood the manifold when the jeep stands after a run. I have come across this fault a couple of times and it is caused by the casting that supports the main jet coming loose from the mail body casting. As the two appear to be pressed together during manufacture a repair might be possible but a replacement carburettor is the better option.

Another part worth checking is the disc valve that operates the choke system. Corrosion or wear can result in poor mating between the surfaces which slide over each other. Provided the damage isn't too bad, lapping the surfaces in with a bit of metal polish can do the trick.

These carburettors were originally manufactured for Hotchkiss by Solex in France and later for the French army by Solex in India. As far as I know they are no longer made but ex-French army stock is still available from the usual dealers of spares in the U.K. and France though stocks are dwindling and prices continue to rise. The datasheets below came with one of these and contain useful information, particularly the second sheet.  N.B. the comment about cold starting i.e. use the choke but do not depress the accelerator pedal! In a world of fuel injection not everyone seems to know this peculiarity of a good old Solex carburettor.

It is of course possible to get an aging and sick carburettor professionally rebuilt. Roger Holness (M201 no. 18088) had his rebuilt by 'Carburetter Exchange' at Leighton Buzzard (01525 371369) which is run by an ex Solex employee who he can thoroughly recommend.  With the stock pile of spares held by dealers diminishing and prices rising a rebuild like this is likely to become a more popular alternative to purchasing a new carburettor. who he can thoroughly recommend.