I was looking for info on how many people on this forum had experience with 28mm Flatslide vs CVK type carbs on the 150-250cc engines. Reason is I am going to stroke my engine, and tighten it up (blueprint) for higher reving (8-9.5k).
I know this thread is older but I have to "correct something.
I set up a Kymco ZX50 several years ago for land speed record runs. Still have the bike, and still ride it from time to time.My best speed to date was 87.3 MPH, and there is still tuning room for improvement.
For LSR runs I set the gear box at a 6:1 final drive ratio. It eats up a Stage6 MKII clutch in thee / one mile runs. Now I have it at 7:1 for street use, and I get around 60-70 miles out of the same clutch.
The bike is 73.4cc, with a Polini top end. The cases have been flow ported, Ruima 4mm stroker crank, custom pipe, ect...
Point is I run a 28mm OKO flatslide on this bike. RPM is the determining factor in what size carb to use. Not cc's
If you set up a 4 stroke to run higher rpm's (8k ish) a larger carb (28mm) will work. In fact it is needed. The only reason to set up a high reving engine is to pump more air faster. The only way to achieve this is to go larger on the intake system.
Now granted, on a putt around town 50-250cc bike the 28mm carb may be too large. I just wanted to add another point of view to this older thread, and perhaps give some food for thought.
If anyone is running a flatslide on their 150, I would sure love to hear about how it is working out.
Trial, and error is one thing but that's why forums exist. Experience rules!!!
