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  1. #1

    Default XS650 single point conversion.

    Since I bought this TX I've done a lot of work on it, including a few mods. I wanted to retain the points system, just simplify it by converting to a single set of points. There was a cam available for this conversion, but apparently they weren't very accurate, so I decided to make my own. First order of business was a backing plate which I made from some 3mm thick steel, shaped it on the lathe, filed cutouts for the minting screws and drilled and tapped the plate for points and lube felt.

    Next I turned down some stock to 18mm, bored it 8mm, filed the ramps, then cut the keyway. Nope, timing was way off. Did it this way for a few attempts without luck. So, I decided to do it in reverse: Cut the keyway, mount the round stock on the advance rod, time the engine, gap the points, set the points at the midway position and mark where the heel of the points counted the round can and file the ramp.
    Attached Thumbnails Attached Thumbnails 2points.jpg   points plate fitted.jpg   polished points cam.jpg   cam keyway end.jpg  

  2. #2


    I managed to get the timing for number one cylinder spot on with the correct dwell after only a few files. Next I rotated the cam 180degrees and did the same for the other ramp, success again. I've since done a little. Fettling and got the timing spot on.

    For this conversion, the two single outlet coils don't work, so I bought a twin outlet coil for CB750, made an ally bracket and polished it and mounted it to the original tab on the frame.
    Attached Thumbnails Attached Thumbnails coil bracket.jpg   timed right.jpg   timed left.jpg   coil bracket and coil fitted right side.jpg  

  3. #3
    Senior Member

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    Apr 2013


    VERY cool mod and a nice maintenance convenience upgrade.

    You might have a batch of plates laser cut and some cams CNC'ed to your spec (degree wheel & digital indicator, and someone including you might have a digital indicator with output that can be recorded). They would not be cheap but quality is worth paying for and the XS community is well established.
    Last edited by farmall; 11-19-2021 at 10:14 PM.

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