[Dchapa10]

Hey,

So this may turn out to be a stupid question and I was just making a simple mistake but, I am having problems with setting the points on my '73 cb350.
I am used a feeler gauge to get the points get the timing generally correct, and now I am using a test light to get the timing perfect. However, when my LF mark is coming around, rather than the test light turning on, it turns off. As long as the points are not touching, the light is on, but as soon as they close and complete the circuit, the light turns off.

I had set the timing before with no problems, but I had recently taken the engine out and put it back in. Before the engine removal, the light would do exactly as it was supposed to, right as that LF mark was coming around, the light would turn on and then turn off until it came back around again. But now with the engine removed and reinstalled, the light stays on and will then turn off when the LF mark comes around.

Like I said earlier, this could end up to be a stupid question with a very easy fix, but I needed some help from some more experienced people as I am new to motorcycles.

Thank you so much in advance for your help.

 

[doode]

The points will open at F and LF

 

[ancientdad]

Hey,

So this may turn out to be a stupid question and I was just making a simple mistake but, I am having problems with setting the points on my '73 cb350.
I am used a feeler gauge to get the points get the timing generally correct, and now I am using a test light to get the timing perfect. However, when my LF mark is coming around, rather than the test light turning on, it turns off. As long as the points are not touching, the light is on, but as soon as they close and complete the circuit, the light turns off.

I had set the timing before with no problems, but I had recently taken the engine out and put it back in. Before the engine removal, the light would do exactly as it was supposed to, right as that LF mark was coming around, the light would turn on and then turn off until it came back around again. But now with the engine removed and reinstalled, the light stays on and will then turn off when the LF mark comes around.

Like I said earlier, this could end up to be a stupid question with a very easy fix, but I needed some help from some more experienced people as I am new to motorcycles.

Thank you so much in advance for your help.

Is your test light connected to positive or ground? It should be connected to ground, and if so the light will come on when the points break. If you somehow pulled the breaker cam from the spark advancer and put it back on 180* out, it might mislead you but I don't think the timing marks would properly coincide.

 

[Dchapa10]

I had a test light that I would connect one end to the points, then would touch the light just anywhere on bare metal on the bike (so ground), then when the points were not touching, the light would be on, and as soon as they touched, the light would shut off. I recently tried connecting the light to the positive end of the battery and touching the light to the wire in the points. Now it is coming on when the points touch.
The engine will not start when I try to start it. All I really did to the engine was adjust the valve clearance, (which I recently double checked to make sure was correct) and adjust the timing on the points.
Prior to removing the engine, the light would come on when the points touched, but now, like I said, it turns off when the points touch as long as I have the light connected to ground.
So I guess my biggest question is: as long as I have this timing lined up, does it matter if my timing light is switching on or off when the points touch? Should that stop the engine from running?

 

[ancientdad]

I had a test light that I would connect one end to the points, then would touch the light just anywhere on bare metal on the bike (so ground), then when the points were not touching, the light would be on, and as soon as they touched, the light would shut off. I recently tried connecting the light to the positive end of the battery and touching the light to the wire in the points. Now it is coming on when the points touch.
The engine will not start when I try to start it. All I really did to the engine was adjust the valve clearance, (which I recently double checked to make sure was correct) and adjust the timing on the points.
Prior to removing the engine, the light would come on when the points touched, but now, like I said, it turns off when the points touch as long as I have the light connected to ground.
So I guess my biggest question is: as long as I have this timing lined up, does it matter if my timing light is switching on or off when the points touch? Should that stop the engine from running?

All you've done by connecting the test light differently is reverse the polarity associated with the opening and closing of the points - but as long as the reaction (bulb on or off, depending on that polarity difference) is occurring at the proper time (F or LF mark accordingly), it wouldn't seem that would be the problem. But again - since you did have the engine out, did you happen to remove the advancer from the end of the cam? If so, did the breaker cam slip off the advance unit? If that is the case, you may have put it back on 180* out. Check to see that the dots on the end of the breaker cam and the advancer shaft line up