Car points question

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Barnbikes

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Picked up an older lawn mower that has a Tecumseh engine in it. The ignition/lighting coil ring is fried.
Thinking of making it battery ignition.
I have scene multiple post about using early 70s dodge point and condenser.
My question is the cam.
Only drawings of a cam I can find on the website is for the webster and it is way to small for this project.
I have a 1" crankshaft. If I make a disk 1.5" OD with a 1.002" ID how big of a flat would I need?
 

Misterg

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It just so happens I have the Webster plans and Fusion360 open:

The Webster cam has a 0.375" wide flat on a 0.688" diameter which gives a max travel of 0.056" on the cam follower (on the points).

To get the same travel on a 1.5" diameter cam, the flat would be 0.569" wide.

It's probably not too critical as long as you can get the correct points gap and the points also close firmly.
 

ShopShoe

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I wonder if your engine really uses that coil for ignition. I have a Tecumseh engine from a riding lawn mower that runs on the usual magneto, but has the coil ring for lighting and to charge the battery for the electric start. I also have a similar Briggs and Stratton that is set up the same way.

I also wonder if it might be easier to wind a new coil than all the other conversion work. Someone on this forum did it several years ago. I tried searching for the post and could not find it.

Just my two cents.

--ShopShoe
 

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