Water Pressure Gauge not indicating on F250D Engine

[rbrich123]

I have a Wellcraft 290 Coastal with twin Yamaha 250D engines. Over the past several years of running (now 400 hours) I have the annoying issue of the water pressure gauge occasionally not indicating any flow. Usually works great after a 100 hour check or requesting maintenance to repair.

Based on all threads I can find and read, this is a common problem with the gauge and due to some form of blockage at the engine connect point. I have studied the maintenance manual, reviewed threads but no where can I find the location on the 250D engine where the pressure line originates. It is not shown within the maintenance manual or any other location.

Can anyone provide where that water pressure gauge feed line originates on the 250D? What is the secret to clearing the line?

[boscoe99]

What is a Yamaha 250D model?

Is this an F250TXRD? What does the data plate on the left hand side of the motor say that the model identity is?

Keep in mind that we are not familiar with your motor. And, we are not mind readers. It is very important that you state the precise model of the motor. Otherwise you may not get meaningful information.

[Sequoiha]

Maybe he means F250B,,

[rodbolt17]

I am very familiar with that engine, just not your question.
flow and pressure have nothing to do with one another.
what is your issue???

I probably have replaced more heads,ex stacks,blocks and piston/rod assy than any other 4 techs in the US,

what gauge package was installed in your well craft???

not all were rigged with Yamaha,not all were rigged with 6y5 not all were rigged with 6y8.

[boscoe99]

I am very familiar with that engine, just not your question.
flow and pressure have nothing to do with one another.
what is your issue???

I probably have replaced more heads,ex stacks,blocks and piston/rod assy than any other 4 techs in the US,

what gauge package was installed in your well craft???

not all were rigged with Yamaha,not all were rigged with 6y5 not all were rigged with 6y8.

What model four stroke (if this is what it is) Yamaha is a 250D?

[boscoe99]

On the assumption that the motor in question is a mechanically con*****ed F250, here is a diagram that shows the tap point for the pressure sense line.

The secret to keeping the block port free and clear is to operate in fresh water. Unfortunately, most can't or don't. Just keep rodding the port orifice clean from time to time.

[boscoe99]

The water pressure tap for a Command Link equipped pressure sensor is depicted below.

[rbrich123]

Yamaha engines

My Yamaha Engines are an F250txr and an Lf250txr. Sorry for the confusing use of flow and pressure. Not sure which gauge package would be correct for an installation using these engines in 2005. Does this information change the locations depicted in the pictures provided?

[99yam40]

reviewed threads but no where can I find the location on the 250D engine where the pressure line originates.

Just curious,
where did the D come from that you posted?

[boscoe99]

My Yamaha Engines are an F250txr and an Lf250txr. Sorry for the confusing use of flow and pressure. Not sure which gauge package would be correct for an installation using these engines in 2005. Does this information change the locations depicted in the pictures provided?

A 2005 model year motor would be identified as an F250TXRD and an LF250TXRD. Yamaha stopped using model year designator letters with the 2005 model year. Yours are what would have been 2006 model year motors.

Here is another photo that depicts where I think your pressure line connects to the block. It agrees with the first photo that I posted. Just look around and you will find the fitting.

Do I assume correctly that you are using analog water pressure gauges? The kind that have a plastic tube that runs from the motor to the gauge?

[rbrich123]

Yes, analog gauge. White hose to the gauge on panel. Called Pro Series gauge. Sent photo in sep message.