Tire Sizing Advice

Hey folks, first timer over here. I purchased a kart a few weeks ago that I believe to be and older Ultamax, when I purchased it the guy threw in some old junk tires. These will definitely need replaced but I have no clue where to start as to proper size of tire, I'll be racing on an approximately 1/8th mile backyard dirt track generally a pretty loose looking. Engine is a predator with a couple minor modifications. If anybody has any advice for me that would be greatly appreciated!


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Site Supporter
Two 8 inch tires on the right side, a 6 inch left rear and a 5 inch left front. These sizes should be on the tires you already have.


Site Supporter
You can run whatever sizes you want on your kart, but typical sizes are both right sides being wider than the rest of them (typically 8.00 or 9.00 wide tire on 10" wide wheels.)
Right sides are typically 11.0X8.10-6 or 12.0X9.0-6 on 10" wide wheels.
The left rear is typically a 11X6.00-6 on 8 1/2" or 8 3/4" wheel (for your track size.)
The left front is typically 10.5X5.00-6 or 10.5X4.50-6 on 6 1/2" wide wheel.

It appears that your kart currently has a narrower RF wheel and tire on it. that may be for clearance on the spindle -- some older karts could not fit a 4" offset RF wheel (typical backside of a 10" wide wheel.)

If you need anything, feel free to reach out to us at the shop number below.

🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN