2005 115 hp running poorly

Hi all, new to the forum but looking for some help with my motor.

It is a 2005 115 and it just isn't running well. It shakes a lot more than usual at idle. It has a lot less power than normal and struggles to plane out the boat. Eventually it will plane out but it is about 10mph short of what it will normally do.

About 3 years ago the fuel/water separator corroded through and the motor sucked in salt water through the fuel system. but that was supposed to be fixed. I don't know too too much about outboards but it feels to me like it is missing on one cylinder maybe? and ideas?

Re: 2005 115 running poorly

Do a compression test ----------------and check that you have spark that will jump a gap of at least 3/8" on all cylinders.

Re: 2005 115 running poorly

you need to test the fuel pressure out of the VST
you can have a bad VST strainer, or even clogged injectors
you need a fuel pressure gauge
they had problems with the TPS sender also on this model

Re: 2005 115 running poorly

How do i check the spark?

Re: 2005 115 running poorly

buy a spark board or spark tester

Re: 2005 115 running poorly

check cylinder compression.