Why is the fuelling so different between cylinders

[davidblythe]

Putting the PC5 on my 1200GSA, the maps between cylinders are very different, much more fuel being added to the right cylinder

with the stories of the 1200 engine dropping right side valves, anyone know why the r/h side cylinder is run so much leaner as standard by BMW

 

[Pukmeister]

Thats an interesting discovery, I never knew the stock fuel map was so different between cylinders, leaning out more on the RH pot. Maybe you are on to something. Perhaps someone at BWM made a cock-up when developing the bike ??

Surely there isn't much physical difference in flow or volumetric performance between cylinders, they breathe from the same pressurised airbox and have roughly the same length inlet and exhaust tracts.

 

[davidblythe]

anyone have any ideas how to post the below so it can be read

 

[Engineer]

Putting the PC5 on my 1200GSA, the maps between cylinders are very different, much more fuel being added to the right cylinder

with the stories of the 1200 engine dropping right side valves, anyone know why the r/h side cylinder is run so much leaner as standard by BMW

Surely more fuel = richer, not leaner??????

 

[st247]

Surely more fuel = richer, not leaner??????

As standard the 1200 runs very lean on the right. To correct it the PC5 has to add more fuel to that cylinder. Hence lean as standard.

 

[Steptoe]

Surely more fuel = richer, not leaner??????

You can have all the computer power in the world but if you don't know the basics .

 

[Engineer]

You can have all the computer power in the world but if you don't know the basics .

Since when did adding more fuel make the resulting fuel-air mixture leaner?

 

[Engineer]

As standard the 1200 runs very lean on the right. To correct it the PC5 has to add more fuel to that cylinder. Hence lean as standard.

OK makes sense - thought you were saying that the PC5 was 'telling you' that it was richer to start with.