How does timing advance work 64 Yachtwin?

[LargemouthBass21]

ive been reading articles about how the timing advance works but nobody seems to actually explain it. They all say just trust me, personally I like to know how things work. So how does the throttle position not affect timing when setting points, but somehow it gets advanced somehow? Also how does the carb linkage adjustment come into play? Thanks

 

[LargemouthBass21]

Somebody on another thread wrote “magneto timing is different than overall timing, what does this mean?

 

[racerone]

When you " time the magneto " you are timing the breaker points in relation to the magnets rotating past the coils.----That gets you the strongest spark.------When the breaker plate / magneto plate rotates the spark changes relative to the motion of the piston in the cylinder.----Sorry , I can not explain it any simpler.------Look at the parts and see how it works.

 

[racerone]

So when you use a timing light on your 64 model 3 HP both plugs fire with the timing marks on the flywheel right between those 2 marks on the magneto plate.-----The rest looks after itself.-----Just an indication of how simple this is.

 

[lindy46]

The carb must be synched to the magneto. There is groove on the underside of the tank mounting ring. When the throttle advance lever aligns with the groove, the carb butterfly should just start to open. If not, you need to loosen the cam on the magneto and adjust in or out to make it so.

 

[LargemouthBass21]

The carb must be synched to the magneto. There is groove on the underside of the tank mounting ring. When the throttle advance lever aligns with the groove, the carb butterfly should just start to open. If not, you need to loosen the cam on the magneto and adjust in or out to make it so.

So it gets the right amount of throttle for the amount of timing it’s getting? That makes sense thank you

 

[LargemouthBass21]

When you " time the magneto " you are timing the breaker points in relation to the magnets rotating past the coils.----That gets you the strongest spark.------When the breaker plate / magneto plate rotates the spark changes relative to the motion of the piston in the cylinder.----Sorry , I can not explain it any simpler.------Look at the parts and see how it works.

That makes a lot more sense thank you. So when you turn the magneto with the throttle lever, it changes the relation between when the spark plug sparks and where the piston is... that helps me a lot thank you

 

[LargemouthBass21]

Ok one more dumb question, the cam has a place on I that’s stamped “top” and there’s a line. Do I align the fiber rubbing part with the line or with the flywheel key? I’ve heard both answers

 

[flyingscott]

The top stands for Top dead center. That is where the points need to be open to .020.

 

[racerone]

Are you sure ??----Would it be marked " top " to make sure the cam is not installed upside down.

 

[LargemouthBass21]

The top stands for Top dead center. That is where the points need to be open to .020.

Ok thank you some people said to have it open to 0.20 at the flywheel key so I was confused... why do people say to line it up with the flywheel key seems like the timing would be way off

 

[LargemouthBass21]

Are you sure ??----Would it be marked " top " to make sure the cam is not installed upside down.

It shows lines though seems like that would be to line things up

 

[LargemouthBass21]

Are you sure ??----Would it be marked " top " to make sure the cam is not installed upside down.

Another thing is that it shows an arrow pointing outward, seems like that would be where to line up the points... where did you get your information from?

 

[racerone]

I use the timing marks on the flywheel and the magneto plate to set the points.----Learned how to do that in 1967 I think.-----That was a long time ago and still use that method.-----Easiest / best way to set the points !!

 

[F_R]

There are two types of cams. Yours is "figure 2". Here is the story, straight from the Horse's mouth:

 

[LargemouthBass21]

There are two types of cams. Yours is "figure 2". Here is the story, straight from the Horse's mouth:

Thank you very much, I will start with that and then use the multimeter method. So for method 2, it can be set anywhere between the flywheel key and the word top

 

[LargemouthBass21]

I use the timing marks on the flywheel and the magneto plate to set the points.----Learned how to do that in 1967 I think.-----That was a long time ago and still use that method.-----Easiest / best way to set the points !!

Like with a multimeter right? I will pick up a multimeter in Monday and do it that way although I wouldn’t call it the “easiest” method

 

[racerone]

But it is the easiest method !!!

 

[Crosbyman]

after the first time… it is a piece of cake… remove the condensers and use the screw holes to pass a small 22 ga wire down to the ohm meter

it is best to use a digital meter (15-20$ will do) for more accuracy but a very very simple flashlight bulb or piezzo buzzer wired in series will do .

just make certain the points are well cleaned with carb cleaner or acetone when done

 

[LargemouthBass21]

after the first time… it is a piece of cake… remove the condensers and use the screw holes to pass a small 22 ga wire down to the ohm meter

it is best to use a digital meter (15-20$ will do) for more accuracy but a very very simple flashlight bulb or piezzo buzzer wired in series will do .

just make certain the points are well cleaned with carb cleaner or acetone when done

Im planning to go out and get a multimeter tomorrow, I’m sure it’ll be useful for other stuff too. I stole a wire from a random wall plug and stripped both ends to use I think it’ll work decently. I cleaned the points alteady with sandpaper, then compressed air to get rid of shavings, then finished it off with carb cleaner and a piece of cardboard. Should I do it again after testing?