1970 merc 75 (7.5.hp) no spark...what is testing procedure?

[roonie]

Hi...wondering what the procedure is for testing for no spark. It was progressively/intermittantly loosing spark and then finally will not run on both cyl. I pulled the lower plug wire ...it would not start.....i pulled the opposite plug wire...it started so i know i have no spark on lower cyl. i just need to know the procedure for what to do next. thanks in advance

 

[roonie]

ive gained some ground on this.....i have discovered i have strong spark, 110 comp. but it seems the fuel bowl adj. was way out. ive adj. the float. What i need to know is since this engine came from CA. USA. and i live in Saskatchewan Canada., could it be that a different main jet is needed due to altitude? CA. USA being aprox. 500 above sea level and Sask. Canada being 1500?