My 1978 105HP engine doe not start

[liusigou]

We have found the ignition system has some issue. Where can I buy one.?So Sad. On saturday it worked but failed in Sunday morning.

 

[Nordin]

What kind of ignition system do you have? Beltdriven Magnapower I with distributor or Magnapower II or Prestolite CD typ.
Pics will help us to figure out.