1987 Johnson 110

[Michaelf0631]

engine will lose power intermittently at full throttle. I have replaced all fuel lines, bulb, filter and fuel pump but engine still loses power!
If someone sits and keeps the bulb pumped up it will run like a scalded dog with no issues. What could be the problem?

 

[James in Canada]

Can the fuel tank breath?
Maybe the fuel tank is developing more vacuum than the fuel pump can overcome.

 

[Michaelf0631]

One thing we haven't checked, I will check and respond.
Thanks!

 

[Michaelf0631]

Blew threw the vent hose, no issues with tank vent!
Anyone have any other recommendations?