XJ600 Diesel bike – Electric decompression release

I do a lot of riding in traffic, and especially during rush hour, I can sit at traffic lights for 2 minutes at a time. As a result, I thought of turning the engine off whilst sitting at these lights to save fuel, as thats what these bikes are all about!

On my L100, I have a remote compression release in the form of a choke cable attached to my fairing. This arrangement is fine when getting going, pull the lever, press starter, release lever off you go. This arrangment is cumbersome if you are at a traffic light and its starting to change so I had the idea of rigging up some sort of electric release so that I could actuate it from a button on the handlebars.

Initially I looked at solenoids, servos and motors but they where either too expensive on their own, or too complicated to control. I then stumbled upon a couple of door lock actuators on ebay. These are essentially 2 wire motors with a gear reduction and a nice hook on the end, apply 12v one way the rod moves in, apply it the other way it moves out. Heres what it looks like:



Its a pretty simple design, and at £5.80 ridiculously cheap. Great for a gamble in case it didnt work.

After I tested it to ensure there was enough movement and force produced I set to work installing it.

I bolted it to the bracing peice that holds my air filter in place, it puts it right in line for the decompression lever. There is enough space for it there and its pretty well hidden. I swapped out my “passing” switch for one that can handle 5 amps current and wired the output to the actuator.

I used a zip tie to attach it to the decompression lever which allows for some fine tuning and is strong enough.


IMG_20140415_152235 IMG_20140415_152258


Here is the manual decompression release:



All in all works pretty well and the engine can be restarted without taking my hands off the handlebars

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2 thoughts on “XJ600 Diesel bike – Electric decompression release

  1. Please can you explain more clearly what the problem is that you’ve fixed ? Do you kick start the engine and this uses stored up compression to restart it ?

    Is it not electric start ?
    What does a decompression release actually do ?

    Please forgive my ignorance, I would just use the kill switch, then clutch in and engine start so I am confused why this is required 🙂


    • So these engines, being a one cylinder, are very hard to get over the compression stroke, even the electric starter stalls.

      to get the engines started, you pull the decompression lever, spin the engine over on the starter until momentum has built up, then release the decompression lever whilst the engine is still spinning. This gives it enough momentum to get over compression and then start.

      Doing this in traffic was a 2 handed thing involving taking one hand off the handlebar to pull the decompression lever. Now I can do it without removing antyhing from the handlebar 🙂

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