Well, the top points should be fully open, so you can set the gap anyway. That's all you do when the points are fully open.Dbailey wrote:So plugs out and 6th gear then rotate the rear wheel in the direction of forward travel is not ok?
Also any thoughts on the cam position picture?
Thanks
Dave Bailey
THEN the actual opening time is when the lines line up - turning the engine in the normal rotation direction of course NOT backwards as we mentioned earlier.
If they don't line up, it's quite possible you have the wrong points - or backplate.
There are two sorts - Kokusan and Denso. Different altogether.
They also have different cams - which affects the points dwell - to allow the different capacitors to charge slightly differently.
Nothing simple is there?
If you fit the wrong points, the timing slots won't allow the points to time correctly.
Soooo, either get the correct ones, or elongate the slots so they timing can actually be times, so to speak.
Fortunately, the different capacitance levels of the different points/cam options doesn't matter toooo much.
Spot the differences.
Well it's the time that the points are open, and that's when the capacitors can charge up, starting when the points open - this takes the spark away from the points and stops the points from getting worn, either by getting a 'tit' on one face, and a cavity on t'other and this causes the timing to usually retard, I believe, and also the coils don't get the extra power from the fully charged capacitor and then the HT voltage at the plugs is less, so there's a weaker spark.
If the wrong capacitor is fitted, or the one there is on it's way out, there will be a spark a the points and this gives the tit/cavity situation as described above.
Oh and dwell can be affected by the points gap too, as a smaller gap will give less dwell - which gives less time for the spark to be extinguished - and a larger gap will give a greater one - which allows a greater time and doesn't matter as much as the spark has gone.
A DC circuit needs better arc suppression than an AC circuit due to the way that an arc is started and the time it's there, otherwise the contact faces erode quickly, even more so than an AC circuit.
However, any electrical switch that opens has a spark across the contacts which can be controlled in different ways, as the actual contact face is very important and needs to be the best as regards resistance. In the case of points, it's by a capacitor - other ways might be blowout coils, magnetic arc expansion, vacuum, extended contact tips - all used in higher current circuit contactors.
Did I mention that I did all this sort of stuff for a loooong time when I actually had a job?
Good innit?!
