R80 G/S air filer ducks

[bernardofeio]

Hello

How many different types of air duck there are for the R100 /R80 engines?

Do they change with the carbs size or with the engine displacement?

I have a R80 with a BBK from siebenrock and I notice that the ducks from the R100 are diferent in diameter

R80 --> one small diam + one bigger diam
R100 --> one big diam + one big diam

 

[bernardofeio]

 

[Gelandestrasse]

Without much thought, is one surface area 80% of the other?

 

[bernardofeio]

two ellipse

area 1 aprox 6cm^2
area 2 aprox 13cm^2

 

[Kenny]

I wouldn't lose any sleep over it, the engine will draw in what it wants

 

[Gelandestrasse]

two ellipse

area 1 aprox 6cm^2
area 2 aprox 13cm^2

6+13=19
13+13=26

19/26=73.1%

Given your approximate area measurements, I think there is strong correlation to my original theory, Holmes.

 

[barny]

I was mystified by "duck" but now it makes sense, bloody preemptive twix.

 

[SteveHop]

6+13=19
13+13=26

19/26=73.1%

Given your approximate area measurements, I think there is strong correlation to my original theory, Holmes.

This is interesting , from Snowbum . https://bmwmotorcycletech.info/R80-fuel-mileage-problems.htm