3.50/4.00-6 Inner Tube with TR13 Straight Valve Stem, 2-Pack, Fits 13x4.00-6; 4.00-6; 3.50-6; 3.50/4.00-6, For Wheelbarrows, For Go Kart

What It Is

This is a 2-pack of 3.50/4.00-6 inner tubes designed for small pneumatic tires on wheelbarrows, go karts, lawn tractors, and utility trailers. The TR13 straight valve stem fits standard tire rims and allows easy inflation with most tire pumps.

Fitment & Compatibility

Before buying, verify these measurements:

• Tire size: Fits 13x4.00-6, 4.00-6, 3.50-6, and 3.50/4.00-6 tires only. Check the sidewall of your current tire for these numbers.
• Rim diameter: 6 inches. Measure the rim bead seat (where the tire sits) – must be exactly 6 inches.
• Valve stem: TR13 straight stem (approx. 1.5 inches long, 0.625-inch hole). Works with most standard wheelbarrow and go kart rims. Not for zero-turn mowers with angled or recessed valve holes.
• Brand/model: Universal fit – no OEM-specific restrictions. Use on any machine with the above tire/rim dimensions.

Key Things to Know

• Quality: Standard rubber butyl tube – fine for light-to-medium use. Not heavy-duty; avoid for commercial or high-speed go kart racing.
• Installation: Easy if you have tire spoons and a compressor. Remove old tube, check rim for sharp edges, lightly powder the new tube, and seat it carefully to avoid pinching.
• Common gotcha: Over-inflation is the #1 failure. Max pressure is typically 30-35 psi; check your tire sidewall. Under-inflating causes tube chafing and punctures.
• 2-pack value: Good for replacing both wheels on a wheelbarrow or having a spare. Price per tube is competitive with single units.

Should You Buy It

This is a solid budget-friendly choice for homeowners replacing worn tubes on wheelbarrows, garden carts, or light go karts. Avoid if you need heavy-duty tubes for rough terrain or high-speed applications – step up to a thicker, reinforced tube instead. Otherwise, it’s a straightforward, low-risk buy.