[Megadan]

Originally Posted by rider1010

Hi, I am getting either the raven or hawk and want to know best carb upgrade. mods will be exhaust, unifilter. should i get a 28mm or 30mm. what jets for chicago, IL area?

thanks for your help in advance. appreciated

So I don't have to type it all again

Originally Posted by Megadan

I have run the PZ30, PZ30B, VM26 (same as PZ30), PWK30, PE30.

THe 30mm smooth bores like the PWK30 and PE30 are definitely too big on a CG250 engine with just an intake and exhaust. With a ported head and cam they are still a tad on the big side, but do work better. They are still very finicky to get the jetting dialed in, and very sensitive to changes in atmospheric conditions. If you want an all out race bike with all of the engine work that goes with it, then a 30-32mm smooth bore is for you.

Otherwise, my suggestion is either a 28mm smooth bore such as the PWK or PE28. These will be the best balance between best power and rideability.

That being said, I have a ported head and cam and I went back to the PZ30B (pumper version of stock style carb) and I am quite happy with it. It may have given up half a HP or so on the very top end, but the low and mid range RPM and idle are strong and steady. Fuel mileage is also a lot better, even with the accelerator pump, over the 30mm smooth bores.