Spark Plug location on Flathead 1

[CSLufkin]

I am planning on machining a new Cylinder Head for my son's Pulling Garden Tractor over the winter. It is a single cylinder Kohler Flathead engine. Any thoughts on what is the best location for the Spark Plug? I know some people say it needs to be directly over the Exhaust Valve, some say centered on the piston, any thoughts?

 

[CSLufkin]

I appreciate your advice...and your crankyness.

 

[RossABQ]

Thundair, interesting that you use a Harley coil on a Norton. I had a '69 G15CS that I had put a 4-cylinder car distributor cam into, with two lobes ground off, and firing a Harley coil. The improvement was dramatic to say the least. It used Standard Blue Streak points for a Chevy, too. It started first kick every time, idled consistently, and the points lasted forever.

As far as dual-wire coils, almost all 4-cyl bike engines use two of them, I got a pair for $5 off a Yamaha at a swap meet. Denso makes almost all of them I think.