26 or 28mm OKO for built 155 GY6?

[CrankingWithCG]

Upon finishing my 155 build, I'm pondering the carburetor. Its a genuine Keihin body, but it was 40 bucks on eBay. Scratches in the bore, not Keihin bowl, and screws. I cannot get it to idle and run good all around. Im going to be throwing a freer flowing Scooterworks pipe on, and I plan on replacing this Frankenstein carb. My only dilemma...ive heard people say a 28 is too big. The current carb has plenty of torque (say for a big bog off the line), is smooth when it wants to be, and has a killer top end. Im thinking by the time i add the pipe, the porting and intake will all together make up for having a 28mm. What's your guys' thoughts on this?

[3strokeengine]

I had a 30mm CVK carb on a 155 and it ran really nice. It all depends on what the engine wants.

Stock cam stick with a stock 24mm carb

But if you got an A9 cam with atleast 10:1 commpression ratio id say run the 30mm cvk carb it will make the most horsepower.

I never liked the 26/28mm carbs never ran like the 24mm it replaced and certainly not like a well setup 30mm carb.

Tuning the 30mm carbs is a bit tricky i my climate ive found they typically run well between a 115 - 125 size main jet, 38 pilot jet works well. Also disable the accelerator pump it adds way too much fuel.

[lilpinny]

I swear by 28 on my 170cc. The 30s are made for 180 and up.