Firestone 1954 3.6 hp Scott-Atwater breaker points question

[awenner]

I'm getting no spark from what appears to be a 1954 Firestone 3.6HP one-cylinder motor. As I rotate the shaft, there appears to be no point at which the breaker opens; nothing on the cylinder seems to be moving the points apart, even slightly; what is supposed to make the points separate?

Thanks!!

[tmcalavy]

The back of the points rub up against an eccentric side of the crankshaft. That point is sometimes labeled Top or is marked with an arrow on the edge of the shaft. You loosen two screws to allow the points to slide in and out, to contact the eccentric, and to lock them back down.

[awenner]

Thank you! As far as I can tell, no part of the breaker unit ever moves the points apart. I am attaching two pictures, one of the breaker unit (I think), and a second where I physically open the circuit by pushing one of the points toward the crankcase shaft. Am I right? There seems to be nothing physically pulling the points apart...nothing from the shaft that turns the propeller also pushes or pulls what I believe to be the points apart.

By eccentric, the only thing I can see is a "flat" side of the shaft with a part number on it...

Thank you for this terrific help!

[F_R]

Thank you! As far as I can tell, no part of the breaker unit ever moves the points apart. I am attaching two pictures, one of the breaker unit (I think), and a second where I physically open the circuit by pushing one of the points toward the crankcase shaft. Am I right? There seems to be nothing physically pulling the points apart...nothing from the shaft that turns the propeller also pushes or pulls what I believe to be the points apart.

By eccentric, the only thing I can see is a "flat" side of the shaft with a part number on it...

Thank you for this terrific help!

Really, you don't see that 'bump" properly called a "lobe" on the cam? Turn the shaft till highest part of the lobe is pushing on the points' rubbing block. At that position, the points' contacts should be .020" apart. If they are not, loosen the hold down screw just a bit and stick your screwdriver in the slot and move the points' base plate till the gap is .020" and retighten the hold down screw. Double check the gap.

[tmcalavy]

Wow FR, great pic showing what I tried to describe. I think you should do a sticky note/post with this pic showing hot to set points, for those who are young enough to have never done it/seen it done.

[awenner]

The picture was very helpful in detailing exactly what I needed to do -- I made the adjustment this morning using the "Breaker points for Dummies" picture and guide, and it started immediately! Now the question is...how long will it last? But that's a phase I am eager to explore! I have to admit, I ballparked the gap; I guess I need a tool that measures the gap exactly to ensure proper firing?

I am very grateful to BOTH of you for your guidance in this, FR and tmcalavy -- and I agree that the labeled picture was exactly what I needed for the concept to gel.

Again, I am deeply appreciative of the help!

AR Wenner

[awenner]

Of course, I need to set the gaps properly, so I spent the $1.98 on a gauge. I knew that sounded dumb the minute I posted it.

[Lion hunter]

The question of how long it will last depends on how long you want to maintain it. 2 of my Scotts (1956 5hp) were bought by my grandpa in the 60's and they still run good today.

[F_R]

The question of how long it will last depends on how long you want to maintain it. 2 of my Scotts (1956 5hp) were bought by my grandpa in the 60's and they still run good today.

I ran my 1947 on Lake Manatee last Monday. Ran great after I got over the case of stupid and put some gas in it. Until then, I couldn't get it started for some reason.