Exhaust Gasket | Honda CT90 / Trail 90

Description

Exhaust Gasket | Honda CT90 / Trail 90

The gasket between your Trail 90’s cylinder head and exhaust pipe is one of those parts you forget exists — until you start hearing a ticking noise at idle. After decades of heat cycles, the original gets compressed flat and buried under carbon. A fresh gasket seals the joint and stops the leak.

Why You Need This

Tick, tick, tick — that rhythmic ticking at idle is the telltale sign of an exhaust leak at the cylinder head. Over decades of heat cycles the gasket gets crushed and carbon-fouled, so coated with soot that it blends into the port and goes unnoticed when the pipe comes off for any other service.

A leaky exhaust gasket does more than make noise. Exhaust gas escaping before the muffler costs you back pressure, which makes carburetor tuning inconsistent. Fresh gasket, proper seal, clean idle.

Specifications

Doing a full rebuild? This gasket is also included as Gasket M in our CT90 Overhaul Gasket Kit. If you’re tearing into the engine, buy the kit instead of ordering pieces.

Installation

Difficulty: Beginner

1. Remove the flange nuts at the cylinder head, then loosen the muffler bracket bolts so the full exhaust comes free. Slide the pipe off.
2. Inspect the exhaust port. If you see bare aluminum, the old gasket came off with the pipe. If the port looks dark and sooty, the old gasket is still in there under a layer of carbon — scrape the carbon off with a small screwdriver until you can see the gasket underneath.
3. Carefully pry the old gasket out of the port.
4. Press the new gasket into the exhaust port.
5. Reassemble in the order the factory sequence is: fit the exhaust pipe flange to the cylinder head and start the flange nuts hand-tight. Tighten the muffler bracket bolts at the frame first, then final-tighten the flange nuts last. This sequence lets the pipe settle into position before the clamping load goes on.