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Ignition timing

Posted: Mon Oct 13, 2008 8:09 pm
by overider
Hi, my moggy has a lead free head and is running on lead free fuel. The question is should the timing be set at the normal marks is it 5 degrees B.T.D.C or should it be advanced or retarded differently. I checked the timing and it appears to be there or there about. However when I turn the ignition off it runs over for a second. :-?

Posted: Mon Oct 13, 2008 8:39 pm
by PSL184
Unleaded fuel usually requires the ignition to be slightly retarded. The best way is to set timing statically (as you have done) then go for a drive and find a nice steady upwards hill. Advance distributor using the vernier until you just get "pinking" when accelerating up the hill, then slightly back off the timing until the "pinking" stops. This will give optimum setting for your engine as they vary so much in state of tune etc you can't give a difinitive reading for every one.

Posted: Mon Oct 13, 2008 11:30 pm
by bmcecosse
The running on indicates something is glowing red inside the combustion chamber - maybe it just need s agood 'blast' to clear it out - but it can happen when running tpp retarded. So as above - advance till it pinks - then retard slightly - that's the optimum setting for your engine. Are the spark plugs in good order - if they have gone 'furry' that could be the glowing red thing!