No spark on my Yamaha 3.5 air cooled

[bikerbill]

Hi all

My 1979 Yamaha 3.5hp air cooled is no longer producing a spark. I have replaced the points but still nothing. How would I check the stator coil and the condensor? and also check if there is a spark at the points?

I believe these are the same motors as the Mariner 3.5, so would the parts be interchangable?

Thanks in advance

Billy

[boats.net]

I'm sure there are tests for those but we don't have any manuals or parts catalogs on that engine here in USA.