2019 15hp EFI

[Capt. Rich]

runs smooth then bogs down to a high rough idle, then runs smooth. Keeps this pattern going and will not run correctly.

 

[Capt. Rich]

I have owned the motor since new and always run ethynol free fuel with marvel mystery oil and techron fuel conditioner

 

[Capt. Rich]

I can't believe problem solved by replacing the spark plugs. I certainly am not complaining. I can't remember when I have had such a simple mechanical fix. I already ordered a fuel separator pump. Jumping to more serious conclusions. The plugs are 2 years old and look fine. Electrodes have an even brownish burn and look good to me, 2 years old. HOORAY!!!!!!!!!!!!!!

 

[Timbodiesel]

Been having same (ish) issues with 13 25 hp 4 efi..replaced fuel line with real fuel line..still same issue..checked plugs as well..looked fine..but may replace also..this is a new issue