Go kart tire issue

I have a small go-kart I'm hoping to make it from a street kart to a field kart. It's tire sizes are 4.10-5nhs 4 lug. It gets high center and the chain hits the ground and stops. I'm thinking bigger tires and smaller sprocket. What is the next rim size?

 

Rim choices depend a lot on the lug pattern you have. On small karts it could be 4X 100mm, 110mm, 4". Diameter of the hub hole in the center also matters.

Unless you have a powerful engine increasing the wheel diameter AND reducing the sprocket size will rob you of so much drive torque the kart may not even get rolling.

 

Not planning an engine upgrade til later on so which would suggest for now, wheel or sprocket?

 

Wheel or sprocket are two totally different things. You wanted a larger "wheel" size to provide more ground clearance. Changing the sprocket will change your gear or drive ratio. If you increase the diameter of your wheel the cart will be faster but have less acceleration. To offset that you may need to change the sprockets to get back closer to the original drive ratio.

If you want more ground clearance I would first look at what tires are available that will fit your existing rims. If you can't find any taller tires then I'd start looking at rim and tire options. Soon I think you'll find that the cost of parts can add up especially with regards to an inexpensive go cart.