Tires wont hold air

[450blj]

I put air in my tires and do about 6 laps and both of my back tires are flat, they are stock rims too, No air leaks when putting them under water. Can anyone suggest anything that could help?

[TRX450RACER174]

Unless you have a beadbreaker take them to a tire shop and have them bust the beads, you probably have dirt or sand in them causing them not to seal.

[YZ400EX]

Originally posted by 450blj
I put air in my tires and do about 6 laps and both of my back tires are flat, they are stock rims too, No air leaks when putting them under water. Can anyone suggest anything that could help?

I had the exact same problem.. when taking corners fast the rear tires would come from the bead just enough to let the air out.. after awhile they were flat.. switched to beadlocks.. no more worries of that happening..