1980 35 hp evinrude lost power

[Bobdag]

What do you mean by decarb? I took the carb off and rebuilt it thinking that was the issue.

 

[Tim Frank]

Check spark with a purpose-built tester...open gap to 7/16". Need a sharp, "snappy" blue spark.
If that is OK, move back to fuel system troubleshooting,

Check fuel pump output pressure with gauge.

 

[Fed]

When you replaced the fuel pump & lines you could have introduced some junk back into the carb if the work was done after the carb job.
The filter is before the fuel pump so you have to be extra careful doing anything after the filter.
Might be worth revisiting the carb.

 

[Bobdag]

When you replaced the fuel pump & lines you could have introduced some junk back into the carb if the work was done after the carb job.
The filter is before the fuel pump so you have to be extra careful doing anything after the filter.
Might be worth revisiting the carb.

The motor started acting up before the carb and fuel pump were done.

 

[Bobdag]

Check spark with a purpose-built tester...open gap to 7/16". Need a sharp, "snappy" blue spark.
If that is OK, move back to fuel system troubleshooting,

Check fuel pump output pressure with gauge.

I bought a tester on my way home tonight. #1 only shoots a tiny spark. Like 1/16
#2 shoots a 1/2". So I'm thinking 2 coil packs are in my future!

 

[jimmbo]

What do you mean by decarb? I took the carb off and rebuilt it thinking that was the issue.

Using a combustion chamber cleaner. Helps free up the piston rings to they are able to expand and contract as the piston moves in the bore. Always a good maintenance procedure

 

[interalian]

I bought a tester on my way home tonight. #1 only shoots a tiny spark. Like 1/16
#2 shoots a 1/2". So I'm thinking 2 coil packs are in my future!

Swap the coils before you buy replacements. Could be something else.

 

[Bobdag]

Ok I'll do that.

 

[Bobdag]

Could I ohm the coil out and see if it's bad?

 

[Tim Frank]

Originally posted by Tim Frank View Post
Check spark with a purpose-built tester...open gap to 7/16". Need a sharp, "snappy" blue spark.
If that is OK, move back to fuel system troubleshooting,

Check fuel pump output pressure with gauge.

I bought a tester on my way home tonight. #1 only shoots a tiny spark. Like 1/16
#2 shoots a 1/2". So I'm thinking 2 coil packs are in my future!

First, I'd only be worried about #1.... the 1/2" on #2 is more than the 7/16" that seems to be the accepted spec.

Second, as someone suggested, swap the "known-good" coil first...could must be at least $50- , and don't really fail as often as they get replaced.
Trouble shoot the circuit for number one, starting with the obvious...do a complete visual sweep, then make sure any connections are tight and corrosion-free.

 

[Bobdag]

Ok so I swapped the coils and ohmed them out also. It is a bad coil. Not the power pack.

 

[Bobdag]

Boat is fixed and running better than ever! Thanks for all the help everyone!

 

[Tim Frank]

Thanks for the update.