T500 timing

[Gorgen]

Hello everybody!
I am new in the forum. I live in Sweden and have been riding bikes since the 70,s. That gives and indication of my age. Right now I have three japanese bikes. A 1972 Suzuki T500 wich I am restoring. And two Yamaha a 1983 RD350 and 2000 XJR1300.
Now to the T500. I am having trouble with setting the timing. I am doing it according to the manual with a lamp and a small battery. To get the timing marks even close I have to set the timing at max retard. I have tried with several new points and condensers but the there is no difference. Opening up the points gap more than specified alters the setting as i should, but that is just a test. Also should I have to disconnect the condensers when setting the timing? When connected the lamp never goes of.

I have also checked the position of the timing marks with a micrometer in the sparkplug hole. The left cylinder is spot on 3,4 mm before TDC. The right one has its mark 2,9 mm before TDC. Nevertheless that should not affect the timing setting in this way. One idea I have on the timing is that the points cam lobe is worn. Is it possible to measure to cam, if so how is this done?
I hope som one has som thoughts about this.

[karl pa]

Welcome to the forum.
The way I set timing is, I measure piston before TDC, take note how close the marks are, then set timing using timing light roughly where the marks were.

[jabcb]

The dwell angle is roughly 180 degrees. So you can end up with one points closing as the other opens.
And the timing light is always on because the other points closes the circuit.

I use a multimeter. The resistance varies between ~ zero & the coil resistances.
The bulb brightness will vary. But depending on the bulb & battery, you may not notice the change.