Has anyone had any experience with boring out their stock carb? I have access to the equipment to do it, but am not sure how far I can go and what else I need to change. For reference, I am on a 87 LT250r with the stock Mikuni Flat Slide carb.
How far can I or should I go, and what jetting changes will I need to do?

 

Howdy,
You could try calling a performance company and ask them. I went from the stock Mikuni VM34SS flat slide to a Keihin 36mm PJ oval slide. Wow what a differance it made, way more low end and a little more on top, but I wanted the low end. The bore of your carb will have alot to do with the type of riding you do and the amount of motor work you have done.


Danno

 

it is the ratio of the AREA of the bore to the AREA of the jet. if you increase the AREA of the bore 10 percent open the main jet AREA by 10 percent

 

it is the ratio of the AREA of the bore to the AREA of the jet. if you increase the AREA of the bore 10 percent open the main jet AREA by 10 percent