Actually, you inquired about flatside carbs and I told you that a flatside without an accelerator pump would be hard to tune. The 40mm that comes on 500 H.O.s are not flatside carbs, but CV carbs. There's a significant difference in the way these two carbs operate. Flatside carbs without accelerator pumps are intended for 2-cycle engines. Flatside pumpers and CVs are typically used on four cycle engines.

 

Oh, im sorry. I thought the 500 H.O. carb was a flatside. I think I will go ahead and buy one and try to jet it myself. Thanks again for the help.