Newbie got '77 85hp partial spark

[Todd_1977_85hp_Johnson]

No known history on this and no experience with outboards. I'm a sterndrive guy and got this $99 18ft Starcraft on ebay. Tried a different power pack and new coil (on #3). Still no spark on #3, intermittent on #1 (when I move timer base arm forward it's better). Good spark on 2 and 4. Timer base looks newer (blue and enclosed) I bought factory manual and am stumped. Pulled flywheel and stator looks good with nothing oozing out. Grounds/connections all checked & retightened. Compression: all around 90psi. Feel good about all I've learned so far and like how easy this is to work on. Thanks in advance.

 

[racerone]

Get battery load load tested.----Pull starter apart for inspection.

 

[Todd_1977_85hp_Johnson]

Get battery load load tested.----Pull starter apart for inspection.

The battery is the one that was with the boat and cranks good, but overall condition is questionable. So thanks! I will make sure a strong capable battery will be on the job now. The starter seems/cranks fine. What benefit will there be to taking it apart/inspecting? I really appreciate the input.

 

[fdrgator]

The suggestion was based on the fact that the motor must be cranking at least 200 rpm to produce spark. An easier approach is simply test for spark with all the spark plugs removed. (It will crank faster with plugs out).