IGNITION SWITCH

IGNITION SWITCH

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  • On 7th April 2015

Warning!  MAKING CUSTOM COMPONENTS COULD BE ADDICTIVE.  Needless to say that in my particular case, the probability implied by “could be” became an absolute certainty. I was hooked. In pursuing simplicity (see Minimalist Approach), I initially pondered the possibility of retaining only the kick start and eliminating the electric start.  Taking this approach a step further, I even considered eliminating the starter motor altogether, but abandoned that thought quickly for fear that this might change the engine’s weight balance.

One of the many challenges in building a custom motorcycle comes, surprisingly, from the freedom the builder has, which, in most cases, is probably restricted only by imagination and  financial resources (and, in the case of some professional builders, by time as well).  Having decided on a component, the builder then has to choose a place for it.  In some cases, it is easy.  A rear fender goes in the back and over the rear wheel. Not much choice there. Handlebars could go on top of the triple tree where they are traditionally found or on the forks as is the case with clip-on’s.  But when it comes to ignition switch and start button, these two components could seemingly go just about anywhere and they don’t have to be combined in the same unit or be even close to each other.

By convention, the ignition switch and start button are always toward the front and around the top near the handlebars.  Cars adhere to a similar convention: the ignition switch in most cases is next to or near the steering wheel.  (Kudos to SAAB engineers who broke with convention when they decided to put the ignition switch on top of the gear box and next to the shift stick and made it so that the driver can only take out the key when the transmission was locked in reverse gear.  You can hot-wire the car all you like.  Try doing the getaway with the car going in reverse. I’ll pay money to see it.)

The idea of having an ignition switch and a start button at the top of the triple tree and near the grips didn’t conform to my design principles since I wanted to keep the handlebars as clean in appearance and as symmetrical as possible.  Plus, putting the ignition switch near the handlebars required running wires to the front.  It seemed to me that a convenient place for these components would be as close to the battery and the starter solenoid as possible.  And the available space right under the right side cover (the battery is an inch behind it) and between the frame’s tubes looked ideal for the ignition switch.

I fabricated a bracket from 1/4″ thick aluminum.  It had a small extension at the top, which was used to mount it to the battery’s metal cage.  The bracket looked like an upside down ace of spades.  I drilled the appropriate size hole in the middle and mounted the ignition switch.  Once the side cover was on, the extension used for mounting the bracket could no longer be seen and the look was nice and clean.

Ignition switch long view

NOTE: A few words about ignition switches.  There are hundreds of  them out there.  The vast majority of the ones that are small enough and have ON-OFF positions only are intended for lawn mowers or some other small engine.  They sell for about $10 – $15 and the quality is extremely poor.  After operating them a few times, the inside blades become loose and contact is erratic.  You’ll know it when you headlight begins to flicker.

I used a simple two-position (ON and OFF) ignition switch.  It had some kind of a cam or spring loaded mechanism inside that keeps it firmly in position and you can feel it as you operate it.  The key turns smoothly and once it is in position it stays there.

Here is a closer view of the ignition switch and the mounting bracket (top left of the image below).

Ignition switch bracket with mounted ignition switch

Since the ignition switch was on the right side and several feet away from the throttle, it made no sense to use a three-position switch with quick return such as used on most vehicles.  I used a separate “momentary” push button mini switch, which would mount on the left of the bike.  I made a bracket for it using 14 gauge aluminum and shaped it so it hugs the frame. The assembly was then mounted to the frame immediately adjacent to the left side cover.  This way, it was within inches of the solenoid.

The push button itself is only a 1/4″ in diameter.  It works perfectly.

Start switch and bracket

Start switch and bracket

So, it is now a three-step process like you see it in the movies.   LIGHTS! Turn the ignition switch on.  CAMERA! Push the start button to engage the starter motor.  ACTION! Twist the throttle and off you go.

QUESTIONSS