twitching in yamaha 1154t

[the viking]

Hello friends I am writing because I have a Yami 115 4 stroke with a 450HS Inyection use about a few erratic 30HS has a fault, the problem is that it always starts to tug a good time to walk at first thought it was the waves but after I realized that no tine nothing to do and it's becoming more important, a few days ago to take honest mechanic I check everything, change spark plugs and fuel filters but after 1 hour of surfing the twitching again, they start at generally over 4500 rpm and 3000 rpm cease about the board does not indicate or voltage or temperature or oil pressure, what I discovered is that if someone is next to the engine and goes pear pressing the fault minimizes or disappears after a few minutes, it is noteworthy that the pear was not compressed but seemed quite normal and hard.
If I can guide would be very useful because the mechanic seems puzzled by this failure
From already thank you very much

[boats.net]

Sounds like starving check for fuel for air leaks in fuel filters or hoses, could be bad mechanical fuel pump.

[the viking]

Thanks for the prompt reply,the fuel line is the first thing we check, we changed all the hoses from the tank to the filter and from there to the pear, checked the diaphragm fuel pump is intact, so the confusion and consultation.
There is a question I have, can be the effect of low oil since the last service was barely above the gridded area and before the rod was a little above, in that I have an auxiliary engine if the level of low oil causes a failure is similar but has an alarm and in this case nothing

[boats.net]

If has low oil pressure buzzer will sound and engine will reduce to 2000 rpm's.
If pumping fuel primer bulb keeps it running then problem is in fuel delivery to vapor tank on engine.