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MG MGA - Carb tuning too rich

Rebuilt a 1500 MGA. Everything has gone smoothly except engine running too rich. Original carbs have new jets and GS needles. Any recommendations as to leaning this engine..perhaps larger needles?
Gary Moore

Is your ignition system up to par? The easiest way to make the engine run leaner is hotter spark. If you have a well built distributor and not something that's never been properly cleaned and lubricated, then maybe consider changing needles.
Do you have the proper (new) spark plugs in it? A fresh cap and rotor? Good points or electronics?
Do you know if the ignition timing is properly adjusted? Just trying to throw some ideas out there.
Jeff
Jeff Schlemmer

Hi Gary. The large cork Jet sealing ring that fits into the dished washer might not be compressed enough. If this cork seal is not compressed enough, the jet stays considerably lower than it should. This can cause a rich mixture, and it's position wont allow enough adjustment to properly lean out the carbs. Look closely at the cork washer. It should be compressed so the visible portion is compressed paper thin. If you see lots of cork seal showing, then the seal is not propery compressed, and you need to tighten the gland sealing nut until the cork seal compresses properly. The cork seal needs to soak in clean motor oil overnight to allow it to become supple enough to compress properly. Good luck, Glenn
Glenn

I had a similar problem that turned out to be caused by inferior quality air filters that came with the reproduction filter boxes. Changed the filters for a reputable make and the problem went away.

Steve
Steve Gyles

This thread was discussed between 16/05/2006 and 17/05/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.