Gas Cap Seal | Honda CT90 / Trail 90

Description

Gas Cap Seal | Honda CT90 / Trail 90

A cracked gas cap seal is the most overlooked fuel leak on a Trail 90. The original rubber — and the even-older cork — seals shrink and harden with age, and fuel starts weeping out from under the cap. This is the OEM-spec replacement seal that drops into your existing CT90 or CT200 gas cap.

Why You Need This

The seal sits inside the twist-on gas cap, pressed flat under the locking tabs. After decades of fuel and heat the rubber goes brittle and the old cork versions crumble — either way, the cap stops sealing and you get the smell of gas and a wet ring around the filler neck. A fresh seal restores a clean seal between the cap and the tank.

This seal fits every CT90 and CT200 gas cap, including the cap on the auxiliary fuel tank Honda added at the K4 — the blank cap on the main tank and the “GAS”-stamped cap on the spare tank both take the same seal.

Specifications

Note: Fits all CT90 and CT200 gas caps, including the auxiliary fuel tank fitted to the K4 and later.

Installation

Difficulty: Beginner

Tools needed: Small flathead screwdriver, wire brush

1. Pop the old seal out of the cap. Old rubber goes brittle and old cork tends to break off in chunks — pick out every last bit so the new seal can seat flat.
2. Clean any rust or corrosion off the inside of the cap with a wire brush so the seal has a clean surface to press against.
3. Stretch the new seal over the cap and work it into place, thin side facing up toward the inside of the cap.
4. Make sure it’s seated flat and fully under the cap’s locking tabs before you twist the cap back on. Take your time — it goes in tighter than you’d expect.