Can anyone tell me what the correct diameter of a "naked" K100 round sealed beam H4 headlight should be ?

Hi Pedro,
I thought they were all oblong, I am sure all those in the fairings were.
Regards,
K-BIKE

K-Bike,
Thanks.
You are right that the RSs and RTs have oblong headlamps but the unfaired K100s and K75s had round lights.
I have a K100 with a non standard fairing and a round headlamp. I need to replace it and I would like to know the diameter of a standard headlight to be sure that it will fit.

According to the original BMW manual its 180mm or a standard 7" in old money. Don't forget to make sure that you obtain one with the correct dip pattern for driving on the 'wrong' side of the road.

We don't have many if any of those here that I have seen anyway. But I suspect that a car headlight could be pressed into service and may be available from a breakers yard.
Regards,
K-BIKE

Many thanks.
Comberjohn - you are right about the dip; that´s why I am changing the headlight
It´s a UK bike that I am reregistering for Spain and I wasn´t sure that the existing light was standard.

I see Motorworks have both UK and Euro versions, but at a price!
K-Bike is right, you could use a unit from a car and save lots of money.

Comberjohn,
Thanks I will follow up.
For sure a new headlight from BMW is prohibitive.
Motorworks is pricey but at least the exchange rate is in my favour