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MG MGB Technical - Pinging - Lean Mixture?

Hi,

I have just fitted K&N air filters to my standard 71 GT & have noticed that i get some pinging when the engine comes under heavy load. I have'nt as yet changed the needles (apprently i should go up from AAU to AAA). Can a lean mixture cause pinging & is the pinging where the mixture is leaning out under heavy load?

I have the AAA needles & plan to change them this weekend, but any comments on the above would be gratefully recieved.

Cheers

Scott
Scott Ralph

Scott,

I have changed to K&Ns last year. And I also fitted the rich needles immediately.
Generally, pinging is a sign of a too much advanced ignition timing or too low octane fuel. Maybe your contact breakers are worn and therefore the ignition timing is a little bit out of the way.

Regards

Mark
Mark

A lean mixture runs hotter, and increased temps can contribute to pinging. Try pulling the choke out a bit and see if that stops the pinging. You may not need to use the AAA needles, unless your jets are already adjusted to max rich.
Paul Konkle

Mark,

the ignition is and illuminition system & the timing currently sits at 8 degrees, factory sittings are 10 degrees. With the old paper filters & cans i never noticed the pinging, this is why i think it may be due to a lean mixture.

Cheers

Scott
Scott Ralph

Mark,

the ignition is the illuminition system & the timing currently sits at 8 degrees, factory sittings are 10 degrees. With the old paper filters & cans i never noticed the pinging, this is why i think it may be due to a lean mixture.

Cheers

Scott
Scott Ralph

This thread was discussed on 28/02/2002

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