Sunday, March 4, 2018

A little more Scrambling

  After a few days of doom and gloom weather reports, New England was still is on the map.  Fighting off the blahs and some depression, I got back into the scrambler.  The magneto was bolted on a few weeks ago, but getting into timing the engine , I feel is one of those events that must be experienced than got through. Timing is the moment that you know where the spark will build the flame wall. its the heart of all you ride on.
In the case of the 67 Scrambler, it has a manual advance unit on the Lucas Magneto.  The first step was to disassemble the old mechanism.  Most everything was wiped down with WD-40 then greased lightly.  The old cable end was formed to fit within the plunger.  I've kept it aside so as to make a replica at a later time. This type of cable end will mean the cable will need to be made with the adjuster housing in place.

The adjuster housing looked to have a fiber washer at the base. Not having the old one or one the right size, I came up with a simple method of wrapping 220 grit sand paper around a socket, then twisting a close fitting fiber washer onto the sand paper. With a little bit of effort the size was a perfect fit.

 It takes a bit of time, to set the timing. I'm always double checking each movement and adjustment.   The first bit was remember which way the engine spins.  Having made the mistake to timing a Velo on the exhaust stroke before, Its a good idea to removed the rocker box and check the rise and fall of both the Intake and Exhaust push rods to find which stroke the engine is on either the exhaust stoke or the power stroke; the power stroke is the one you want for timing.  Most of the Velos I have are happy with 38 to 36 degrees before TDC  (Top Dead Center) even with ethanol. After I'm comfortable with which direction the engine is spinning At that point I'll setup a degree wheel on using the positive stop method.
Not pictured, is the wire indicator pointing to the degree wheel. In this case, I used a coat hanger filed to a point. the Back end was bent into a 'U' shape then clamped down under one of the engine bolt nuts on the right hand side.  After the degree wheel is set, the magneto points are set to open at 36 degrees (full advance: advance lever in its resting position, or closed). I'll test this several times; both with the  advance lever in different positions. When the cigarette paper lightly slides out of the points, it should coincide with the pointer on the timing wheel.

While the cover is off I'll give the rocker adjusters a gap check.
Next step will be to begin cable making for the rest of the controls.