The Keihin Fcr Pumper Single Carb. has the Advantage of Better Fuel metering, An accelerator pump, Flat slide, Ease of Adjustment #1, How about parts availability ! !
In my Experience with 4-Stroke Singles, CV carbs have way too much lag, Flat Spots off idle, & Throttle position changes.
That rubber diaphragm is doomed, from day 1. And it won't get better with age.
FCR pumper carbs have the best throttle response. Try one you'll see ! Can't beat that squirt of fuel at Every twist !
That's why all the Top Performance 4-Stroke Tuner's use the FCR's on both, Single & Multi -Cyclinder engines.(MX, EN, Flat track & Road Racing)
When they aren't Running EFI.$$$$$$$$$$$Cost$$$$$
Twin Carbs need to be on Twin Cyclinder engines. Never understood twin carbs on a Thumper, Honda Tried, on a few Thumpers.
Thank Goodness that did'nt last long.But, Your right about Emissions. EPA Rules all over the Motorcycle industry.
Give me a Big Thumper & a Single Pumper Carb
Performance & Mileage are miles apart,
when it comes to Carbs.If i wanted Big Mileage, I'd ride an Electric Scooter !
I want SUMO !
