Forum bmwbike.com

Hi Beemers,
are you using fuel additif to replace lead,
as old engines have bean running on leaded fuel.
Ciao

Lead was used in old gas primarily to increase octane. The lead also had some benefit in cushioning the impact of the valves on their seats. However this same lead accumulated as deposits in the combustion chamber and on the spark plugs, which was not desirable.
Unleaded gas has worked well in our old motors and caused no valve recession, with exception of some mid-1980 airheads, which had soft metal valve seats. A lead additive is of no benefit unless you are racing your old motor or going long distances at high rpms.
Lead additive is no longer legal in the USA. And the current "lead substitutes" are undesirable because they cause excessive deposits on the valves and in the combustion chamber.
So don't use additives.

Hi, Thank You for your comment. JS