Forum bmwbike.com

I have old bikes and I'm affraid, because fuel will be modiffied and I don't know if leaded fuel is essencial or the bikes will be OK whit the unleaded fuel.

Hi,
You can find various messages concerning this issue by typing in "lead free", "unleaded", or similar in the search box on the upper part of this page and clicking the search button.
You will notice that opinions slightly differ from each other. Some say, they are running their old engines with unleaded fuel without any problems. Others fear that they might experience damages. There are no messages reporting about immediate problems. It also depends on the model and actual way of using your bikes. Let us say a R25/3 only used at moderate speed compared to an R69S used for racing. Most agree that the best time for a lead free conversion is once the cylinder heads are due for an overhaul anyhow. Once you order new valves, make sure that you have or order the correct upper valve caps,valve locks
and valve guides. If you mess up those you will have an immediate problem, regardless what kind of fuel you are using.

Best regards

Thorsten

Leaded fuel was introduced after WW2, so it is not needed for post vinatge and earlier engines. I use a lead substitute and I made up to now no negative experiences. The R 68 has meanwhile new valve seats.

Best regards

Thomas

Thanks a lot, I will be quiet