Taking on my CB160 65 Revive project has introduced me to others, in the cyber world, which are owners of the same bike. One of those people is Andrew who has his own garage project in the works with his own CB160. His bike, Lucille, is getting an engine overhaul this winter season to freshen things up for the next riding season. If you’re interested in checking out his progress you can visit his blog Meet Lucille.

I felt as though I have done my CB160 rebuild coverage to death on the blog lately. It’s too bad because I have a long ways to go yet. Anyway…in an effort to get back to fabricating I opted to perform a small machining task for Andrew in order to help make a small contribution to his project.

Andrew has planned to get rid of the electric starter on his bike and rely solely on the kick-starter (or push start). My original plan was to do the same thing with my bike however the rear sets were going to interfere with the kick-starter therefore I opted to get rid of the kick-starter and keep the electric start. I wasn’t happy with the decision to maintain the extra pounds associated with the starter however the bike needs to be practical and streeteable.

Here is what the factory starter looks like installed on the CB160 engine.

So where is this heading? Well when the starter is removed permanently you need to be able to fill the empty hole with something that will keep the dirt out and the oil in. These items are known as starter block off plates. I am unsure what is available for block off plates in the aftermarket world; I never looked or researched it. I already had one mentally designed for my bike but then never got the chance to build it. Well I looked back in my brains archives and found the engineering drawn still filed away, I figured it was still there since the archives typically don’t get trashed for 2 years or so.

So with Lucille in need of a plate and me with an idea I figured it was time to unite the two and make something happen. The plan was to build a plate that required no modifications to the engine, look clean, stay put, and seal the oil. The material of choice was a section of solid 6061 aluminum round stock. Lately I have been telling my stories through pictures so I will continue the format this time as well. Follow along.

In order to machine the block off plate for Lucille I used my mock up engine that is currently installed in my bike. The hole on the left side is what needs to be filled. The idea is to machine a plug that gets installed from the inside of the side cover. The side cover bolted on is what will prevent the plug from backing out and a landing machined onto the plug will keep it from falling out from the other side. Confused? Just look at the pictures, you’ll get it.

Here are my collected necessities. My spare starter for taking measurments, a chunk of 3″ 6061 aluminum and an assortment of O-rings in hopes that one will work.

The overall depth of the plug is aproximately 1.600″ so I started by cutting off a 2″ section of aluminum to chuck up into the lathe.

This is the visible end of the block of plate machined down to spec. The diameter is the same as the factory starter housing diameter.

I machined in a groove in order to fit the o-ring seal. I made the groove just a hair wider the the o-ring thickness in order to allow for the compressing of the ring.

Here I have the other side of the plug turned down to spec. This is the side that will contact the side cover. The plug is getting parted off to within a few thou of its final dimension.

Here is the completed block off plate. You can see the landing that was machined into the center section. This landing is what will prevent the plug from coming out of the case.

Since the plug is going to be installed from the inside, the case needed to be cleaned up. The sharp edge was smoothed out, using a flap wheel, in order to prevent the o-ring from being cut while being installed.

Here is the installed position from inside the case. A little bit of white lithium grease on the oring and the plug slid in beautifully. You can now get a better idea of how the side case cover, once bolted on, will keep the plug put.

And here is what is visible from outside the engine. It looks super clean which is just how I like it. Hopefully Lucille will appreicate the addition.

  1. meetlucille says:

    Thanks Gord.
    The block-off plate arrived today and will be fit shortly. I will let you know how she likes it.


    • gordsgarage says:

      Hey Andrew, glad the plate showed up. Something I forgot to mention is the case bolt needs to be loose when installing the plate. The case bolt I speak of it the one that is kind of like a “pinch” bolt for the starter. Once the plate is installed then that final bolt can be threaded in and secured.

      Hopefully the plate fits.


  2. meetlucille says:

    Hi Gord.
    I have successfully installed the block-off plate.


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