Yamaha 115 four stroke missing

[boat help]

I have a low hour 2006 Yamaha 4 stroke. Has been running great, last week refueled and ever since it has developed a miss at idle and when trying to accelerate, it will not make power, max rpm about 3000 when in the water under a load(in gear.) when on the hill it misses at idle and at all rpm. appears to be running rich (a little smoke) it will make rpm when not under a load.

checked the fuel filter ----all clear
checked the plugs all look good, cleaned and replaced.
checked for fire and have it at all cylinders.

any suggestions would be great and appreciated!

 

[rodbolt]

Re: Yamaha 115 four stroke missing

check the VST filter and the prefilter, better is to check fuel rail pressure at the problem RPM and load.

 

[boat help]

Re: Yamaha 115 four stroke missing

Thanks for the suggestion. i had checked the prefilter, appears clean, but not the vst---it will take a little time to get to it!!
I do not know how to check the rail pressure or what it should be? any help there?