Board index All Things Vintage points timing question on old XR

points timing question on old XR

A place to relive, revive, and ride that "old iron".

Post Tue Jul 28, 2020 1:26 pm

Posts: 663
working on an XR with points and a 6v system. The bike has no battery, so I used a 12v bike battery to set up my static timing light - you know, turn the mag until light dims and it should dim at the F mark. But it does not work no matter how points are set.

Do I need to use a 6v battery to perform this test?
Ride On.

Post Tue Jul 28, 2020 7:10 pm

Posts: 257
I have used this method on my MR back when it had points.

I think for sure you may need a 6V battery and a 6V light bulb. Not because it might not work with a 12V battery but because with the 12V you might not see the brightness change because it can be very subtle from my experience and a 12V might be to bright. If you have the headlight you can just use the bulb from that. Also make sure you have a good ground. You can use one of those big old flashlight 6V batteries. They have them in the camping section at Walmart still. They really aren’t used for much otherwise nowadays.

The ultimate way to do this is with an ohm meter. Then you can see the numbers change or even better an old analog one where you can watch the dial drop when the points open signaling the break in continuity.

Post Wed Jul 29, 2020 2:40 pm

Posts: 663
ratsMC wrote:
I have used this method on my MR back when it had points.

I think for sure you may need a 6V battery and a 6V light bulb. Not because it might not work with a 12V battery but because with the 12V you might not see the brightness change because it can be very subtle from my experience and a 12V might be to bright. If you have the headlight you can just use the bulb from that. Also make sure you have a good ground. You can use one of those big old flashlight 6V batteries. They have them in the camping section at Walmart still. They really aren’t used for much otherwise nowadays.

The ultimate way to do this is with an ohm meter. Then you can see the numbers change or even better an old analog one where you can watch the dial drop when the points open signaling the break in continuity.


Thanks! yes the 12V would not dim so has to be the 6v issue. Never thought of the ohm meter, good one.
Ride On.


Return to All Things Vintage