POINTS OPENED OR CLOSED

[Anonymous-0]

MODEL C, MY POINTS ARE CLOSED ON NO. 1 PLUG WHEN AT TOP DEAD CENTER, IS THIS CORRECT OR SHOULD AJUST, IF SO HOW?

 

[old]

Please loose the cap lock people drop not like to be yelled at LOL. That said if I remember right at TDC yes the points would be closes since you want the spark plug to fire right at or close to TDC and to fire the spark the points need to clse

 

[steve(ill)]

as you are rotating the crank toward TDC, the point will be closed and you will see the cam lobe on the distributor heading toward the foot on the point. When you get to TDC, the lobe will contact the foot of the point and just start to open it. When the point starts to open, the spark from the coil goes to the plug and it fires. Under the distributor there is a lock bolt that hold the unit into the engine block. Loosen the bolt and rotate the distributor so the cam lobe is touching the point at TDC. If you are over 90 degrees off, move the #1 spark plug wire to that location. After you are done, rotate the crank and stop at FIRE on the crank. YOu will see the point is 20-30 degrees from opening. Grab the rotor and turn it ( spring loaded weighted) and it should advance the unit and touch the point . This is the "run" position when the motor is above 800 RPM - advance.

 

[old]

Ok so your saying I am back wards on my thinking right?? Which is ok just want to make sure I am getting it right been to long since I really did think about it since it is one of those things I have never really thought about I just do it with out thinking about how it works if that makes sense

 

[John T]

I havent owned a C in years but can give you some general advice.

If youre setting static timing at TDC when the piston is at TDC the points should just be breaking open as thats when the plug will fire. If too soon before she can kick back if too late the performance isnt as good. Now if its a distributor ignition with mechanical RPM based advance once youre running at RPM the points will break open maybe 15 to 20 BTDC.

You can set static start timing (by having plug out but it grounded and wire attached with ignition on and slowly hand cranking engine to TDC) by first retarding the timing,,,,,,take piston to TDC,,,,,,then slowlyyyyyyyyy advance timing until the plug fires n lock her down. Or you can do it with ignition off and using a continuity checker or test lamp on the points at TDC to lock her down when the points just open (break continuity and/or light comes on)

John T

 

[steve(ill)]

hea old, just think about it that the point is grounding the spark so it cant go to the spark plug. Once the point opens, the spark plug is the path of least resistance from the coil, and it sparks !

 

[ShadetreeRet]

When the piston is at TDC are you sure it is on the compression stroke and not the exhaust stroke? Just a thought. And yes, as someone already said, when it fires the points should be open. When the points are closed current is building in the coil, when they open that current is shunted to the spark plug.

 

[Bob Huntress]

If the distributor rotor is hitting the nomber one spot on the cap as the piston is getting to TDC, and the points should be opening at the same point. As Shadetree mentioned, the piston will reach TDC twice for every fire of the spark plus, therfore the points will only open every other time the piston reaches TDC. If you are running a 2 stroke, which an original C engine isn't, the breaker points will open each time the piston approaches TDC. Another way to determine which stroke the piston is on as it reaches TCD is to watch the valves with the valve cover removed. As the piston goes from BDC to TDV and the exhaust valve opens the spark plug should not be firing. If both valves are closed as the piston approaches TDC and remain cose as the piston starts to go back down, that the one the spark plug should fire on. Think of it this way. The valves are closed for compression and power, while intake opens for intake stroke and exhaust opens for exhaust stroke.

 

[teddy52food]

There is no connection between the primary curcuit and the spark plug other than a magnetic field. Where did you ever come up with an idea like that?