2014 250 Yamaha SHO Knocking Noise

[aschiem]

My 2014 Yamaha 250 SHO started making a knocking noise the other day. We thought it could have been bad gas because it had been sitting in the tank for a while and didn't have that pungnet gas smell. Drained the tank and took it out on the water to test it and it was still knocking. We took it to our mechanic and they ran the motor and they said the low oil pressure alarm started going off. They checked the oil levels and everything seemed fine there. They looked at the ecu recorder and it said that the motors low oil pressure alarm had gone off 30 times since we have gotten the motor. I have not heard the alarm go off at all since I have owned the boat.

What could be making my motor knock?

Why haven't I heard the low oil pressure alarm?

[Randy T]

Go see how loose your flywheel is

[Dando]

If the knocking is related to low oil pressure (and most likely it is from what you've said)......It'll need teardown attention (rebuilt or new block).

[munchie]

Did they tell you in what time frame the alarm went off 30 times. 30 in the last ten minutes or over the past year? I wonder if you can tell the difference from the readout?.

And was it still knocking when the mechanic ran it. All I saw was you said he saw low oil pressure

[mcyama]

Typically everything is lies or misdirection! First understand, what a "knock" is. Then proceed slowly. remove gearcase drain plug and examine "debris" on magnet. Remove oil filter and cut open, examine for "debris". If unit is under warranty, don't touch!! Bring to a Dealer. ThanksMartin

[Charlie206]

My HPDI computer says I've had a couple hundred overheats. The engine has never been hot.

[Dando]

If it was under warranty, I'd charge my trolling motor batteries and head to the lake. That'd tell if it was something, or nothing.

[Champ]

if you have analog gauges that are not yamaha it will show over heat every time you start it

[Buzz Cut]

On my 14 250 SHO the only time my low oil pressure alarm came on was about .3 seconds beofre she started knocking like a diesel engine on ether.Needless to say a new power head had to be installed. This was at the 130 hr mark.