1977 4.5 Mercury Won’t start

[Himey7826]

Hi all. I have a 1977 Mercury 4.5 hp single cylinder outboard that has been a basement for 40 years. I had to rewire because of bad wire insulation, I replaced impeller, and cleaned and new gaskets on carb. I get spark on the motor, I sprayed carb cleaner in the carb just to get it going. It has started for a couple seconds but then dies, and won’t restart. I set the carb idle screw at 1 1/2 turns. Fresh gas mixed at 50:1 ratio. I tried installing a nova 2 electronic ignition chip thinking maybe something going on with stator but get no spark after chip installed. Compression test was at 90. Running out of ideas, and any input or help is much appreciated! Thanks in advance

 

[Scott Danforth]

first, welcome aboard

second, throw the chip away, its junk. put the ignition back to what it should be

your compression is a bit low, most likely from sitting. have you tried using ring-free?

did you chase all the passages in the carb?

 

[Himey7826]

Thanks for reply! I did throw chip away. I cleaned points and reset to .018. I cleaned all passages in carb actually twice to make sure it was well cleaned. One thing I’m not sure of is when I set the points, I have read they need to be set on high point of cam. How do I determine the high point in the cam? I haven’t tried ring-free going to look into that now. Thanks again for reply! Just wanted to add...this motor was only used twice before being put away where it sat for so long. It looks brand new which is pretty neat for its age