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MG MGB Technical - SU Carburetter mixture

The Haynes MGB Owners Workshop manual states:
"To enrich the mixture turn the screw anti-clockise"

The Haynes SU Carburettor Owners Workshop manual states:
"Turn clockwise to enrich"

Obviously one of the above is incorrect. Which direction do I turn to enrich the mixture.

Maybe if I had to do this more than every 5 years I would remember.
LS Sheldon

Unscrew it (ie anti-clockwise) to enrich the mixture. That moves the jet further from the needle thus allowing more fuel to flow.
Miles Banister

If you are adjusting the mixture on an HIF carburetor, you do have to turn it clockwise to enrich. The mechanism is a right angle lever, and not a direct device as moving the jet on HS carburetors.

warmly,
dave
Dave Braun

Sorry, should have said HS carb.
Lee

On an HS whether you turn it clockwise or anti-clockwise to richen depends on how you look at the jet adjusting nut. If you could look at the bottom of the carb on car while turning the nut then it would be anti-clockwise to richen. But as most people will probably be looking down on top of the carb while reaching underneath to turn the nut, they will be turning it clockwise to richen. It's easiest to think of unscrewing the nut, i.e. tending to move the jet lower with respect to the carb body, to richen the mixture. Clear as mud?

HIF is much easier - screw it in i.e. clockwise to richen, unscrew it i.e. anti-clockwise to weaken as has been said.
Paul Hunt

I remember the HIF way, this way: Right is Rich, Left is Lean....
Willem van der Veer

Thanks a lot Willem, that's a pretty easy way not to forget it!

Regards
RG
Renou

This thread was discussed between 25/10/2008 and 28/10/2008

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