32 vs 40mm bings on R100GS?

[newguy]

my R100Gs is an American import and therefore has the 32mm bing carbs. what are the performance differences compared to the 40mm bing models?

 

[Beemerboff]

Bings are CV, or Constant Velocity carbs ,and are designed to keep the intake velocity,err, constant.

So the practical differences between a properly set up pair of each are not noticable in everyday riding.

Two 32 mm carbs flow enough for around 90 hp so if you plan a real hot motor you might want something a bit larger, but otherwise not much to gain.

 

[Rob Farmer]

There's a red 100GS that appears occasionally in the three picture windows at the top of the screen. It was owned by several of us on this site. It's American spec with the 32mm carbs and is one of the fastest airheads I've ever ridden. When I had it the bike was completely standard and even had the air system installed. All of the rubbers in the carb were perished though and needed replacing to get it to run well.

I wouldn't even entertain fitting lager carbs to a bike already fitted with 32's. After all the dyno time I've had with my 100PD it's obvious the standard airbox doesn't work with the larger carbs, with 32mm carbs the airbox is spot on.

 

[newguy]

thanks for the info. My intention was never to switch to 40. Just wanted to know the difference.