How to replace the ignition keyswitch – Honda CT90 Trail, Honda CT110 Postie Bike

The ignition switch is located on the left hand side of the frame, just behind the headstock. It pokes out through a hole in the plastic fairing piece that sits over it – this guide starts at the point where you have removed said fairing piece and can see the switch:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

There’s a Honda special tool for removing the nut that surrounds it; if you don’t have one of those you can use a drift or punch and a hammer to loosen it (anticlockwise as usual):

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Removed:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Now you should be looking at this:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

On the flipside there should be a rubber bung covering the opposite side of the switch; on this bike it has been removed and you can see the back of the switch:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Wiggle the switch out backwards through the hole on the right hand side:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

On the early 90s CT110 we have four wires coming out of the switch leading to the wiring loom – the CT90s have two from memory but we haven’t got one handy to confirm that with:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

These are just bullet connectors and should be able to be easily disconnected. You may wish to check the condition of the connectors while you have them disconnected; make sure they aren’t corroded or loosely fitting.

The new switch, off eBay:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

It comes with a small rubber gasket and a thicker nut:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

There’s also a rubber cover on the back side that we couldn’t get to fit inside the CT110’s gap – it’s easy enough to remove if you also can’t get it to fit:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

The rear of the switch:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Disconnect the old wires, hook up the new ones – matching colours:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Push the ignition switch through from the right side – making sure that you align the frame tab in the hole with the cut-out as you can see here:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Rubber gasket in place:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

New nut in place, installed with a drift once it got hand-tight due to lacking the Honda tool or the desire to make a custom socket – note that the new nut on this particular unit doesn’t fit through the hole in the plastic downtube fairing piece:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

Original Honda unit on the left, new one on the right:

Here's how to replace the ignition keyswitch on a Honda CT90 or CT110 trail or postie bike, as shown on MotoFaction.org.

We ended up taking off the new nut and re-using the old Honda piece so as to be able to use the downtube fairing piece again.

…and you’re done!

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