Yamaha Engine cut out at 2000rpm

[flabob123]

I have twin 2004 HPDI 150 engines. Advancing the throttle above 2000rpm it cuts out and if not returned to idle it will stop .Engine was run while not in gear.
Thinking of having a fuel problem I have changed the fuel/water separator filter, Fuel lines and removed the check valve at the tank. It starts good and idles at 650 to 700 rpms. Any suggestion would be appreciated'

Bob

[robert graham]

Maybe engine is going into automatic 2000 RPM safety mode due to high temperature or problems with oiling system....this feature can offer some protection for your motor....good luck!...

[99yam40]

monitor the fuel pressures to see if and were the restriction is located
Lots of filter/screens in those motors

[Seacraft12]

No alarms? Check to see if you buzzer works. Sounds like it may be going into that safe mode but it is usually accompanied by an alarm. Digital or analog gauges? If digital, is it flashing low oil? Do a search on here on how to test the alarm buzzer. If it is broken, fix that first.

[Biminibrad]

Motors

Change vst filters, low pressure pumps,fuel strainer. If that does not do it probably mystery filters on hi pressure pump.also verify shift switch is not hung up, it kills two cylinders.

[rodbolt17]

monitor the medium and high pressure pump at the SAME time.
the HP can be monitored with a volt meter.
the shift switch cuts two cylinders in N and 4 cylinders when in N and the RPM exceeds about 1500.
there again its on or off and easily monitored with an Ohm meter(engine off) or a volt meter,engine running.

NO alarms or switchs or sensors will STALL the engine.

[flabob123]

Engine 150 HPDI cuts out at 2000 RPM'S

Thanks guys for all the help listed below. I checked and found the theimo sw's OK OK, sensor OK, Buzzer Ok, Fuel Press OK, Haven't checked the Shift Position sw. yet. Changed all the fuel filters except the vst one . I finely called a mechanic over and put the computer on and found that the 02 sensor was not putting out any voltage. He was coming back with a sensor . That was over a week ago, backed up with work. MY question is could a O2 sensor cause my problem?. Also how could I check and what are the resistance reading I should get checking the Shift Position Switch . Thanks again Guys, Bob

[99yam40]

did you test fuel pressures at the problem RPM?
Testing while it is working OK is good to see it meets spec, but you need to test while problem shows up also to see which/what is changing.

I am sure a bad O2 sensor will not shut off a motor

[rodbolt17]

on the HPDI, the O2 sensor feedback voltage is NOT used above about 1500 RPM. rules that out.
also if tested on a flusher you typically get a low or 0 volt reading.
gear case MUST be submerged and the engine warmed up BEFORE any valid testing can be done on the O2 sensor.

I still vote for a fuel rail pressure issue.

the resistance readings on ANY switch are ON or OFF.
0 ohms or infinite ohms .

its kinda like a light switch on the wall, its ON or its OFF.

unlike a SENSOR which implys a variable resistance.

this leads to why some literature CAN be misleading, its called jinglish or swienglish depending on if your dealing with Japanese built and translated or swedeish(Volvo).

cannot tell you how funny it is to read about a motor running a fever.