CKRC Forums

Hello, I recently decided to get into karting and have gotten a Briggs and Stratton kart that is set up for senior. I am a Junior and am wondering what I need to modify on my cart to convert it to Junior? I think you need 6 inch tires instead of 7.1 inch. Also, I believe you need to change the throttle slide. On the overdrive website it says Junior 1 and Junior 2 Throttle slide and I don’t know the difference. Please Help.

Welcome to karting! The max rear width on JR2 is 50 inches, and does require a 6’ wheel/tire combo. It’s worth looking first at what size is currently on the rear as there was a period where SR ran the 6’ tire as well. JR2 also uses the gold slide.

Thanks for the help. I am just wondering what is the difference between JR1 and JR2? I am currently running 7.1 inch tires on the back. Does that mean I am good for tires in Junior?

JR1 is the cadet kart. So it uses 4.6 tires on all 4 corners. JR2 requires the 6’ tire.

So I need 6 inch tires on the rear to convert it to Junior?

Correct. To the best of my knowledge you need a 6’ wheel as well. And then the maximum rear width from outermost edge of the wheel to the other wheel is 50’.

I am not sure what size wheel fits the 6 inch tire?

You can stretch it onto a 7’ wheel, but I believe junior requires the 6’ rim regardless along with tire. Under downloads there is the supplemental regs and ASN technical book. You can refer to those to confirm. Hope that helps.