Anyone knows a good rule of thumb on what size of carb you should use depending on the bore size?

Why not just use bigger jets with a PJ or PWK35 or 36?
Instead of using a PJ or PWK 38, 30 or 40.

This drives me nuts.

Me to, i was going to get a bigger carb for my blaster and this guy said that after all the jetting it will be the same as stock, i was like what the crap. :?

The bigger carb flows more air(bigger opening for the air to get into). When you increase the size of the engine, or do mods that allow more airflow(filter, pipe, airbox lid mods, and the biggest-porting) restricting it at the carb is not always a good idea. Try around the block breathing through a straw. Walking=stock motor. Not that big a deal right? Now try running around the block breathing through a straw. Running=bigger/modified motor. Now you know why people get bigger carbs. :cheese:

Bigger Bore=Bigger Carb.
Stock Bore=stock carb or slightly bigger carb.
If u get a bigger carb dont go overboard unless u port or bore it out. If u get a bigger carb on a stock bore only get a slightly bigger carb maybe by 4mm probably nothin bigger than that or it will be harder to get all that are in through the small port.

Hey Aftermarket, is that a stock size you are running? I suspect not, right?

I had a 265 LRD Niks kit with national porting installed on my quad. I was using an air striker pwk38 with 55 and 175. I poked a hole the size of a quarter at the center of a brand new frikin expensive pro-x piston after one hour of use.

I never had problems before with the stock cylinder at 300 and major porting.

I went with a pwk 38 rather than a PJ36 that LRD suggested and still threw my money to the can.

Superman, thanks for the insightful information.

Yeah I Live about 4 blocks away from ECC.

I got a new piston too. But I will have to crack open the cases.
Lots of particles got there.

Be waiting for your report.