I bought a troy bilt tiller for 150 dollars. It has the following numbers. serial 5009D

Block stamped 136457. On the casing it also says 354-Y. Can any info be provided on the date of manufactur.

Also, I have a magneto with points and condenser. Can I convert to a solid state to avoid points adjustments?

I lost the spark and get it sporadically? I suspect the coil? The day before it ran good but when engaging the tines it would bog down and die when put in dirt. I suspect the coil is weak due to the lose of power? What is the correct gap for sparkplug, and points? Thanks for any help